description: Alice has recently received an array a_1, a_2, ..., a_n for her birthday! She is very proud of her array, and when she showed her friend Bob the array, he was very happy with her present too!
  
  However, soon Bob became curious, and as any sane friend would do, asked Alice to perform q operations of two types on her array:
  
    * 1 x y: update the element a_x to y (set a_x = y). 
    * 2 l r: calculate how many non-decreasing subarrays exist within the subarray [a_l, a_{l+1}, ..., a_r]. More formally, count the number of pairs of integers (p,q) such that l ≤ p ≤ q ≤ r and a_p ≤ a_{p+1} ≤ ... ≤ a_{q-1} ≤ a_q. 
  
  
  
  Help Alice answer Bob's queries!
  
  Input
  
  The first line contains two integers n and q (1 ≤ n, q ≤ 2 ⋅ 10^5) — the size of the array, and the number of queries, respectively.
  
  The second line contains n integers a_1, a_2, ..., a_n (1 ≤ a_i ≤ 10^9) — the elements of Alice's array.
  
  The next q lines consist of three integers each. The first integer of the i-th line is t_i, the operation being performed on the i-th step (t_i = 1 or t_i = 2).
  
  If t_i = 1, the next two integers are x_i and y_i (1 ≤ x_i ≤ n; 1 ≤ y_i ≤ 10^9), updating the element at position x_i to y_i (setting a_{x_i} = y_i).
  
  If t_i = 2, the next two integers are l_i and r_i (1 ≤ l_i ≤ r_i ≤ n), the two indices Bob asks Alice about for the i-th query.
  
  It's guaranteed that there is at least one operation of the second type.
  
  Output
  
  For each query of type 2, print a single integer, the answer to the query.
  
  Example
  
  Input
  
  
  5 6
  3 1 4 1 5
  2 2 5
  2 1 3
  1 4 4
  2 2 5
  1 2 6
  2 2 5
  
  
  Output
  
  
  6
  4
  10
  7
  
  Note
  
  For the first query, l = 2 and r = 5, and the non-decreasing subarrays [p,q] are [2,2], [3,3], [4,4], [5,5], [2,3] and [4,5].
solution: import sys
  import os
  from io import BytesIO
  
  if sys.version_info[0] < 3:
      sys.stdin = BytesIO(os.read(0, os.fstat(0).st_size))
  
  f = sys.stdin
  if os.environ.get('USER') == "loic":
      f = open("data.in")
  
  line = lambda: f.readline().strip('\right\n').split()
  
  def write(w):
      sys.stdout.write(w)
      sys.stdout.write("\n")
  
  
  class Data:
      def __init__(self, pref, suff, first, last, sz, res):
          self.pref = pref
          self.suff = suff
          self.first = first
          self.last = last
          self.sz = sz
          self.res = res
          
      def __str__(self):
          d = self.__dict__
          res = ""
          for k,v in d.items():
              res += str(k) + " : " + str(v) + "\n"
          return res
          
  def merge(a, b):
      #################################
      if a is None and b is not None:
          return b
      if b is None and a is not None:
          return a
      if a is None and b is None:
          return None
      #################################
      
      sz = a.sz + b.sz
      first = a.first
      last = b.last
      res = a.res + b.res
      
      pref = a.pref
      suff = b.suff
      
      if a.last <= b.first:
          res += a.suff * b.pref
          if a.suff == a.sz:
              pref = a.suff + b.pref
          if b.pref == b.sz:
              suff = b.pref + a.suff
      
      return Data(pref,suff,first,last,sz,res)
      
  class SegmentTree:
      def __init__(self, arr):
          self.n = len(arr)
          self.sz = 1<<(self.n-1).bit_length()
          self.data = [None] * 2 * self.sz
          
          for i in range(self.n):
              self.data[self.sz + i] = arr[i]
          for i in range(self.sz - 1, 0, -1):
              self.data[i] = merge(self.data[i<<1], self.data[i<<1|1])
   
   
      def update(self, pos, new_val):
          i = self.sz + pos
          self.data[i] = new_val
       
          while i > 1:
              i >>= 1
              self.data[i] = merge(self.data[i<<1], self.data[i<<1|1])
          
      def query(self, l, r):
          tl = self.sz + l
          tr = self.sz + r + 1
          res_left = None
          res_right = None
       
          while tl < tr:
              if tl & 1:
                  res_left = merge(res_left, self.data[tl])
                  tl += 1
              if tr & 1:
                  tr -= 1
                  res_right = merge( self.data[tr], res_right)
              tl >>= 1
              tr >>= 1
       
          return merge(res_left, res_right)
  
  def solve():
      res = []
      st = SegmentTree(ARR)
      for _ in range(Q):
          c,l,r = map(int,line())
          if c == 2:
              res.append(st.query(l-1,r-1).res)
          else:
              st.update(l-1, Data(1, 1, r, r, 1, 1))
      
      return "\n".join(str(e) for e in res)
  
  T = 1
  for test in range(1,T+1):
      N,Q = map(int,line())
      D = list(map(int,line()))
      
      ARR = []
      for i in range(N):
          ARR.append(Data(1, 1, D[i], D[i], 1, 1))
      
      write(solve())
      
  f.close()