#include <bits/stdc++.h>
using namespace std;
using ll=long long;
using ld=double;
using vll=vector<ll>;
#define FOR(i,a,b) for(ll i=a;i<(ll)b;++i)
#define ROF(i,a,b) for(ll i=a;i>=(ll)b;--i)
#define PB push_back

int main(){
  ios::sync_with_stdio(0);cin.tie(0);
  int N;
  scanf("%d", &N);
  std::vector<int> a1(N);
  std::vector<int> a2(N);
  std::set<std::pair<int, int>> s;
  for (int i = 0; i < N; ++i)
  {
    int x, y;
    scanf("%d %d", &x, &y);
    a1[i] = x;
    a2[i] = y;
    s.insert({x, y});
  }

  long long c = 0;
  for (int i = 1; i < N; ++i)
  {
    int u1 = a1[i] - a1[0];
    int u2 = a2[i] - a2[0];
    bool possible = true;
    //printf("%d %d\n", a1[i], a2[i]);

    for (int j = 1; j < N; ++j)
    {
      if (j == i) continue;

      int p1 = a1[j] - u1;
      int p2 = a2[j] - u2;

      int q1 = a1[j] + u1;
      int q2 = a2[j] + u2;

      if (s.count({p1, p2}) == 0 && s.count({q1, q2}) == 0)
      {
        possible = false;
        break;
      }
    }
    if (possible)
      ++c;
    //printf("\n");
  } 
  printf("%lld\n", c * 2);

  return 0;
}