#include <bits/stdc++.h>
using namespace std;

#define fastio                  ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
#define input_output            freopen("input.txt", "r", stdin); freopen("output.txt", "w", stdout); 

template <typename Arg1>
void prn(Arg1&& arg1) { cout<<arg1<<"\n";}
template <typename Arg1, typename... Args>
void prn(Arg1&& arg1, Args&&... args) { cout<<arg1<<" "; prn(args...); }

template <typename Arg1>
void prs(Arg1&& arg1) { cout<<arg1<<" ";}
template <typename Arg1, typename... Args>
void prs(Arg1&& arg1, Args&&... args) { cout<<arg1<<" "; prs(args...); }

template <typename Arg1>
void read(Arg1&& arg1) { cin>>arg1; }
template <typename Arg1, typename... Args>
void read(Arg1&& arg1, Args&&... args) { cin>>arg1; read(args...); }

#define int                     long long
#define all(ds)                 ds.begin(), ds.end()
#define uniq(v)                 (v).erase(unique(all(v)),(v).end())
#define gcd(x,y)                __gcd(x,y)
#define rep(i,a,b)              for(int i=a;i<b;i++)
#define precise(x)              cout<<fixed<<setprecision(x)
#define endl                    "\n"

const long long INF = 1e18;
const int32_t MOD = 1e9+7;
const int N = 1005;

int n, m, k, q, r, l, x, y, z;
int a[N], b[N], c[N];
string s, t;
int ans = 0;


float findSlope(pair<int, int>p1, pair<int, int>p2){
    int x = p2.second - p1.second;
    int y = p2.first - p1.first;
    return (float)(float(x)/(float(y)));
}

void solve(){
    read(n);
    pair<int,int>a[n];
    rep(i,0,n){
        int x, y;
        read(x, y);
        a[i] = {x,y};
    }
    for(int i = 0; i < n-1; ++i){
        for(int j = i+1; j < n; ++j){
            float z = findSlope(a[i], a[j]);
            // prn(z);
            if(z >= -1.0 && z <= 1.0){
                ans++;
            }
        }
    }
    prn(ans);

}

signed main()
{
#ifndef ONLINE_JUDGE  
    input_output  
#else   
    fastio
#endif

#ifdef SIEVE
    sieve();
#endif

#ifdef NCR
    init();
#endif

    int t = 1;
    // cin>>t;
    while(t--){
        solve();
    }

    return 0;
}
#include <bits/stdc++.h> 
using namespace std;
// #define LOCAL // 提出時はコメントアウト
#define DEBUG_

typedef long long ll;
const double EPS = 1e-9;
const ll INF = ((1LL<<62)-(1LL<<31));
typedef vector<ll> vecl;
typedef pair<ll, ll> pairl;
template<typename T> using uset = unordered_set<T>;
template<typename T, typename U> using mapv = map<T,vector<U>>;
template<typename T, typename U> using umap = unordered_map<T,U>;

#define ALL(v) v.begin(), v.end()
#define REP(i, x, n) for(int i = x; i < n; i++)
#define rep(i, n) REP(i, 0, n)
#define sz(x) (ll)x.size()
ll llceil(ll a,ll b) { return (a+b-1)/b; }
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }
template<class T> vector<vector<T>> genarr(ll n, ll m, T init) { return vector<vector<T>>(n,vector<T>(m,init)); }

///// DEBUG
#define DUMPOUT cerr
#define repi(itr, ds) for (auto itr = ds.begin(); itr != ds.end(); itr++)
template<typename T>istream&operator>>(istream&is,vector<T>&vec){for(T&x:vec)is>>x;return is;}
template<typename T,typename U>ostream&operator<<(ostream&os,pair<T,U>&pair_var){os<<"("<<pair_var.first<<", "<<pair_var.second<<")";return os;}
template<typename T>ostream&operator<<(ostream&os,const vector<T>&vec){os<<"{";for(int i=0;i<vec.size();i++){os<<vec[i]<<(i+1==vec.size()?"":", ");}
os<<"}";return os;}
template<typename T,typename U>ostream&operator<<(ostream&os,map<T,U>&map_var){os<<"{";repi(itr,map_var){os<<*itr;itr++;if(itr!=map_var.end())os<<", ";itr--;}
os<<"}";return os;}
template<typename T>ostream&operator<<(ostream&os,set<T>&set_var){os<<"{";repi(itr,set_var){os<<*itr;itr++;if(itr!=set_var.end())os<<", ";itr--;}
os<<"}";return os;}
void dump_func(){DUMPOUT<<endl;}
template<class Head,class...Tail>void dump_func(Head&&head,Tail&&...tail){DUMPOUT<<head;if(sizeof...(Tail)>0){DUMPOUT<<", ";}
dump_func(std::move(tail)...);}
#ifndef LOCAL
#undef DEBUG_
#endif
#ifdef DEBUG_
#define DEB
#define dump(...)                                                          \
DUMPOUT << "  " << string(#__VA_ARGS__) << ": "                            \
        << "[" << to_string(__LINE__) << ":" << __FUNCTION__ << "]"        \
        << endl                                                            \
        << "    ",                                                         \
    dump_func(__VA_ARGS__)
#else
#define DEB if (false)
#define dump(...)
#endif

//////////

#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")

vector<ll> divisors(ll n) {
    vector<ll> res;
    REP(i,1,int(sqrt(n))+1) {
        if (n%i==0) {
            res.push_back(i);
            
            if (i!=n/i)
                res.push_back(n/i);
        }
    }
    return res;
}


int main() {
    #ifdef LOCAL
    ifstream in("../../Atcoder/input.txt");
    cin.rdbuf(in.rdbuf());
    #endif

    ll N, ans = 0;
    cin>>N;

    N *= 2;
    for (auto n : divisors(N)) {
        ll r = N / n;
        if ((r-n-1) % 2 == 0) ans++;
    }

    cout << ans << endl;


    return 0;
}
