description: This is the easy version of the problem. The only difference from the hard version is that in this version all coordinates are even.
  
  There are n fence-posts at distinct coordinates on a plane. It is guaranteed that no three fence posts lie on the same line.
  
  There are an infinite number of cows on the plane, one at every point with integer coordinates.
  
  Gregor is a member of the Illuminati, and wants to build a triangular fence, connecting 3 distinct existing fence posts. A cow strictly inside the fence is said to be enclosed. If there are an odd number of enclosed cows and the area of the fence is an integer, the fence is said to be interesting.
  
  Find the number of interesting fences.
  
  Input
  
  The first line contains the integer n (3 ≤ n ≤ 6000), the number of fence posts which Gregor can choose to form the vertices of a fence.
  
  Each of the next n line contains two integers x and y (0 ≤ x,y ≤ 10^7, x and y are even), where (x,y) is the coordinate of a fence post. All fence posts lie at distinct coordinates. No three fence posts are on the same line.
  
  Output
  
  Print a single integer, the number of interesting fences. Two fences are considered different if they are constructed with a different set of three fence posts.
  
  Examples
  
  Input
  
  
  3
  0 0
  2 0
  0 4
  
  
  Output
  
  
  1
  
  
  Input
  
  
  5
  0 0
  2 16
  30 14
  4 6
  2 10
  
  
  Output
  
  
  3
  
  Note
  
  In the first example, there is only 1 fence. That fence is interesting since its area is 4 and there is 1 enclosed cow, marked in red.
  
  <image>
  
  In the second example, there are 3 interesting fences. 
  
    * (0,0) — (30,14) — (2,10) 
    * (2,16) — (30,14) — (2,10) 
    * (30,14) — (4,6) — (2,10) 
solution: 
  def divisors(M):
      d=[]
      i=1
      while M>=i**2:
          if M%i==0:
              d.append(i)
              if i**2!=M:
                  d.append(M//i)
          i=i+1
      return d
  
  def popcount(x):
      x = x - ((x >> 1) & 0x55555555)
      x = (x & 0x33333333) + ((x >> 2) & 0x33333333)
      x = (x + (x >> 4)) & 0x0f0f0f0f
      x = x + (x >> 8)
      x = x + (x >> 16)
      return x & 0x0000007f
  
  def eratosthenes(n):
      res=[0 for i in range(n+1)]
      prime=set([])
      for i in range(2,n+1):
          if not res[i]:
              prime.add(i)
              for j in range(1,n//i+1):
                  res[i*j]=1
      return prime
  
  def factorization(n):
      res=[]
      for p in prime:
          if n%p==0:
              while n%p==0:
                  n//=p
              res.append(p)
      if n!=1:
          res.append(n)
      return res
  
  def euler_phi(n):
      res = n
      for x in range(2,n+1):
          if x ** 2 > n:
              break
          if n%x==0:
              res = res//x * (x-1)
              while n%x==0:
                  n //= x
      if n!=1:
          res = res//n * (n-1)
      return res
  
  def ind(b,n):
      res=0
      while n%b==0:
          res+=1
          n//=b
      return res
  
  def isPrimeMR(n):
      d = n - 1
      d = d // (d & -d)
      L = [2, 3, 5, 7, 11, 13, 17]
      for a in L:
          t = d
          y = pow(a, t, n)
          if y == 1: continue
          while y != n - 1:
              y = (y * y) % n
              if y == 1 or t == n - 1: return 0
              t <<= 1
      return 1
  def findFactorRho(n):
      from math import gcd
      m = 1 << n.bit_length() // 8
      for c in range(1, 99):
          f = lambda x: (x * x + c) % n
          y, r, q, g = 2, 1, 1, 1
          while g == 1:
              x = y
              for i in range(r):
                  y = f(y)
              k = 0
              while k < r and g == 1:
                  ys = y
                  for i in range(min(m, r - k)):
                      y = f(y)
                      q = q * abs(x - y) % n
                  g = gcd(q, n)
                  k += m
              r <<= 1
          if g == n:
              g = 1
              while g == 1:
                  ys = f(ys)
                  g = gcd(abs(x - ys), n)
          if g < n:
              if isPrimeMR(g): return g
              elif isPrimeMR(n // g): return n // g
              return findFactorRho(g)
  def primeFactor(n):
      i = 2
      ret = {}
      rhoFlg = 0
      while i*i <= n:
          k = 0
          while n % i == 0:
              n //= i
              k += 1
          if k: ret[i] = k
          i += 1 + i % 2
          if i == 101 and n >= 2 ** 20:
              while n > 1:
                  if isPrimeMR(n):
                      ret[n], n = 1, 1
                  else:
                      rhoFlg = 1
                      j = findFactorRho(n)
                      k = 0
                      while n % j == 0:
                          n //= j
                          k += 1
                      ret[j] = k
  
      if n > 1: ret[n] = 1
      if rhoFlg: ret = {x: ret[x] for x in sorted(ret)}
      return ret
  
  def divisors(n):
      res = [1]
      prime = primeFactor(n)
      for p in prime:
          newres = []
          for d in res:
              for j in range(prime[p]+1):
                  newres.append(d*p**j)
          res = newres
      res.sort()
      return res
  
  def xorfactorial(num):
      if num==0:
          return 0
      elif num==1:
          return 1
      elif num==2:
          return 3
      elif num==3:
          return 0
      else:
          x=baseorder(num)
          return (2**x)*((num-2**x+1)%2)+function(num-2**x)
  
  def xorconv(n,X,Y):
      if n==0:
          res=[(X[0]*Y[0])%mod]
          return res
      x=[X[i]+X[i+2**(n-1)] for i in range(2**(n-1))]
      y=[Y[i]+Y[i+2**(n-1)] for i in range(2**(n-1))]
      z=[X[i]-X[i+2**(n-1)] for i in range(2**(n-1))]
      w=[Y[i]-Y[i+2**(n-1)] for i in range(2**(n-1))]
      res1=xorconv(n-1,x,y)
      res2=xorconv(n-1,z,w)
      former=[(res1[i]+res2[i])*inv for i in range(2**(n-1))]
      latter=[(res1[i]-res2[i])*inv for i in range(2**(n-1))]
      former=list(map(lambda x:x%mod,former))
      latter=list(map(lambda x:x%mod,latter))
      return former+latter
  
  def merge_sort(A,B):
      pos_A,pos_B = 0,0
      n,m = len(A),len(B)
      res = []
      while pos_A < n and pos_B < m:
          a,b = A[pos_A],B[pos_B]
          if a < b:
              res.append(a)
              pos_A += 1
          else:
              res.append(b)
              pos_B += 1
      res += A[pos_A:]
      res += B[pos_B:]
      return res
  
  class UnionFindVerSize():
      def __init__(self, N):
          self._parent = [n for n in range(0, N)]
          self._size = [1] * N
          self.group = N
  
      def find_root(self, x):
          if self._parent[x] == x: return x
          self._parent[x] = self.find_root(self._parent[x])
          stack = [x]
          while self._parent[stack[-1]]!=stack[-1]:
              stack.append(self._parent[stack[-1]])
          for v in stack:
              self._parent[v] = stack[-1]
          return self._parent[x]
  
      def unite(self, x, y):
          gx = self.find_root(x)
          gy = self.find_root(y)
          if gx == gy: return
  
          self.group -= 1
  
          if self._size[gx] < self._size[gy]:
              self._parent[gx] = gy
              self._size[gy] += self._size[gx]
          else:
              self._parent[gy] = gx
              self._size[gx] += self._size[gy]
  
      def get_size(self, x):
          return self._size[self.find_root(x)]
  
      def is_same_group(self, x, y):
          return self.find_root(x) == self.find_root(y)
  
  class WeightedUnionFind():
      def __init__(self,N):
          self.parent = [i for i in range(N)]
          self.size = [1 for i in range(N)]
          self.val = [0 for i in range(N)]
          self.flag = True
          self.edge = [[] for i in range(N)]
  
      def dfs(self,v,pv):
          stack = [(v,pv)]
          new_parent = self.parent[pv]
          while stack:
              v,pv = stack.pop()
              self.parent[v] = new_parent
              for nv,w in self.edge[v]:
                  if nv!=pv:
                      self.val[nv] = self.val[v] + w
                      stack.append((nv,v))
  
      def unite(self,x,y,w):
          if not self.flag:
              return
          if self.parent[x]==self.parent[y]:
              self.flag = (self.val[x] - self.val[y] == w)
              return
  
          if self.size[self.parent[x]]>self.size[self.parent[y]]:
              self.edge[x].append((y,-w))
              self.edge[y].append((x,w))
              self.size[x] += self.size[y]
              self.val[y] = self.val[x] - w
              self.dfs(y,x)
          else:
              self.edge[x].append((y,-w))
              self.edge[y].append((x,w))
              self.size[y] += self.size[x]
              self.val[x] = self.val[y] + w
              self.dfs(x,y)
  
  class Dijkstra():
      class Edge():
          def __init__(self, _to, _cost):
              self.to = _to
              self.cost = _cost
  
      def __init__(self, V):
          self.G = [[] for i in range(V)]
          self._E = 0
          self._V = V
  
      @property
      def E(self):
          return self._E
  
      @property
      def V(self):
          return self._V
  
      def add_edge(self, _from, _to, _cost):
          self.G[_from].append(self.Edge(_to, _cost))
          self._E += 1
  
      def shortest_path(self, s):
          import heapq
          que = []
          d = [10**15] * self.V
          d[s] = 0
          heapq.heappush(que, (0, s))
  
          while len(que) != 0:
              cost, v = heapq.heappop(que)
              if d[v] < cost: continue
  
              for i in range(len(self.G[v])):
                  e = self.G[v][i]
                  if d[e.to] > d[v] + e.cost:
                      d[e.to] = d[v] + e.cost
                      heapq.heappush(que, (d[e.to], e.to))
          return d
  
  #Z[i]:length of the longest list starting from S[i] which is also a prefix of S
  #O(|S|)
  def Z_algorithm(s):
      N = len(s)
      Z_alg = [0]*N
  
      Z_alg[0] = N
      i = 1
      j = 0
      while i < N:
          while i+j < N and s[j] == s[i+j]:
              j += 1
          Z_alg[i] = j
          if j == 0:
              i += 1
              continue
          k = 1
          while i+k < N and k + Z_alg[k]<j:
              Z_alg[i+k] = Z_alg[k]
              k += 1
          i += k
          j -= k
      return Z_alg
  
  class BIT():
      def __init__(self,n,mod=0):
          self.BIT = [0]*(n+1)
          self.num = n
          self.mod = mod
  
      def query(self,idx):
          res_sum = 0
          mod = self.mod
          while idx > 0:
              res_sum += self.BIT[idx]
              if mod:
                  res_sum %= mod
              idx -= idx&(-idx)
          return res_sum
  
      #Ai += x O(logN)
      def update(self,idx,x):
          mod = self.mod
          while idx <= self.num:
              self.BIT[idx] += x
              if mod:
                  self.BIT[idx] %= mod
              idx += idx&(-idx)
          return
  
  class dancinglink():
      def __init__(self,n,debug=False):
          self.n = n
          self.debug = debug
          self._left = [i-1 for i in range(n)]
          self._right = [i+1 for i in range(n)]
          self.exist = [True for i in range(n)]
  
      def pop(self,k):
          if self.debug:
              assert self.exist[k]
          L = self._left[k]
          R = self._right[k]
          if L!=-1:
              if R!=self.n:
                  self._right[L],self._left[R] = R,L
              else:
                  self._right[L] = self.n
          elif R!=self.n:
              self._left[R] = -1
          self.exist[k] = False
  
      def left(self,idx,k=1):
          if self.debug:
              assert self.exist[idx]
          res = idx
          while k:
              res = self._left[res]
              if res==-1:
                  break
              k -= 1
          return res
  
      def right(self,idx,k=1):
          if self.debug:
              assert self.exist[idx]
          res = idx
          while k:
              res = self._right[res]
              if res==self.n:
                  break
              k -= 1
          return res
  
  class SparseTable():
      def __init__(self,A,merge_func,ide_ele):
          N=len(A)
          n=N.bit_length()
          self.table=[[ide_ele for i in range(n)] for i in range(N)]
          self.merge_func=merge_func
  
          for i in range(N):
              self.table[i][0]=A[i]
  
          for j in range(1,n):
              for i in range(0,N-2**j+1):
                  f=self.table[i][j-1]
                  s=self.table[i+2**(j-1)][j-1]
                  self.table[i][j]=self.merge_func(f,s)
  
      def query(self,s,t):
          b=t-s+1
          m=b.bit_length()-1
          return self.merge_func(self.table[s][m],self.table[t-2**m+1][m])
  
  class BinaryTrie:
      class node:
          def __init__(self,val):
              self.left = None
              self.right = None
              self.max = val
  
      def __init__(self):
          self.root = self.node(-10**15)
  
      def append(self,key,val):
          pos = self.root
          for i in range(29,-1,-1):
              pos.max = max(pos.max,val)
              if key>>i & 1:
                  if pos.right is None:
                      pos.right = self.node(val)
                      pos = pos.right
                  else:
                      pos = pos.right
              else:
                  if pos.left is None:
                      pos.left = self.node(val)
                      pos = pos.left
                  else:
                      pos = pos.left
          pos.max = max(pos.max,val)
  
      def search(self,M,xor):
          res = -10**15
          pos = self.root
          for i in range(29,-1,-1):
              if pos is None:
                  break
  
              if M>>i & 1:
                  if xor>>i & 1:
                      if pos.right:
                          res = max(res,pos.right.max)
                      pos = pos.left
                  else:
                      if pos.left:
                          res = max(res,pos.left.max)
                      pos = pos.right
              else:
                  if xor>>i & 1:
                      pos = pos.right
                  else:
                      pos = pos.left
  
          if pos:
              res = max(res,pos.max)
          return res
  
  def solveequation(edge,ans,n,m):
      #edge=[[to,dire,id]...]
      x=[0]*m
      used=[False]*n
      for v in range(n):
          if used[v]:
              continue
          y = dfs(v)
          if y!=0:
              return False
      return x
  
      def dfs(v):
          used[v]=True
          r=ans[v]
          for to,dire,id in edge[v]:
              if used[to]:
                  continue
              y=dfs(to)
              if dire==-1:
                  x[id]=y
              else:
                  x[id]=-y
              r+=y
          return r
  
  class SegmentTree:
      def __init__(self, init_val, segfunc, ide_ele):
          n = len(init_val)
          self.segfunc = segfunc
          self.ide_ele = ide_ele
          self.num = 1 << (n - 1).bit_length()
          self.tree = [ide_ele] * 2 * self.num
          self.size = n
          for i in range(n):
              self.tree[self.num + i] = init_val[i]
          for i in range(self.num - 1, 0, -1):
              self.tree[i] = self.segfunc(self.tree[2 * i], self.tree[2 * i + 1])
  
      def update(self, k, x):
          k += self.num
          self.tree[k] = x
          while k > 1:
              self.tree[k >> 1] = self.segfunc(self.tree[k], self.tree[k ^ 1])
              k >>= 1
  
      def query(self, l, r):
          if r==self.size:
              r = self.num
  
          res = self.ide_ele
  
          l += self.num
          r += self.num
          while l < r:
              if l & 1:
                  res = self.segfunc(res, self.tree[l])
                  l += 1
              if r & 1:
                  res = self.segfunc(res, self.tree[r - 1])
              l >>= 1
              r >>= 1
          return res
  
      def bisect_l(self,l,r,x):
          l += self.num
          r += self.num
          Lmin = -1
          Rmin = -1
          while l<r:
              if l & 1:
                  if self.tree[l] <= x and Lmin==-1:
                      Lmin = l
                  l += 1
              if r & 1:
                  if self.tree[r-1] <=x:
                      Rmin = r-1
              l >>= 1
              r >>= 1
  
          if Lmin != -1:
              pos = Lmin
              while pos<self.num:
                  if self.tree[2 * pos] <=x:
                      pos = 2 * pos
                  else:
                      pos = 2 * pos +1
              return pos-self.num
          elif Rmin != -1:
              pos = Rmin
              while pos<self.num:
                  if self.tree[2 * pos] <=x:
                      pos = 2 * pos
                  else:
                      pos = 2 * pos +1
              return pos-self.num
          else:
              return -1
  
  import sys,random,bisect
  from collections import deque,defaultdict
  from heapq import heapify,heappop,heappush
  from itertools import permutations
  from math import gcd,log
  
  input = lambda :sys.stdin.buffer.readline()
  mi = lambda :map(int,input().split())
  li = lambda :list(mi())
  
  n = int(input())
  xy = [mi() for i in range(n)]
  for i in range(n):
      x,y = xy[i]
      xy[i] = (x//2,y//2)
  
  parity = [0 for i in range(4)]
  for x,y in xy:
      p = 2 * (x&1) + (y&1)
      parity[p] += 1
  
  res = 0
  for i in range(n):
      for j in range(i+1,n):
          x0,y0 = xy[i]
          x1,y1 = xy[j]
  
          if (x0-x1)&1==0 and (y0-y1)&1==0:
              t = 0
          else:
              t = 1
  
          for p in range(4):
              x2 = p>>1 & 1
              y2 = p & 1
  
              tmp = t
  
              if (x0-x2)&1 or (y0-y2)&1:
                  tmp += 1
              if (x1-x2)&1 or (y1-y2)&1:
                  tmp += 1
  
              if tmp&1==0:
                  plus = parity[p]
                  if 2 * (x0&1) + (y0&1)==p:
                      plus -= 1
                  if 2 * (x1&1) + (y1&1)==p:
                      plus -= 1
                  res += plus
  
  print(res//3)
  