asdasdas

#include <iostream>
#include <bits/stdc++.h>
#include <stdio.h>
#include <math.h>
#include <cmath>

using namespace std;
pair<double,double> bruh;
map<int,pair<double,double>> dude;
set<int> s;

int main() {
    int n,i,k,j,sum=0;
    double x,y;
    int min = INT_MAX, max = INT_MIN;
    scanf("%d",&n);
    for(i=0;i<n;i++) {
        scanf("%lf %lf",&x,&y);
        s.insert(x);
        bruh = make_pair(x,y);
        dude[x] = bruh;
        if(x<min) {
            min = x;
        }
        if(x>max) {
            max = x;
        }
    }
    for(i=min;i<=max;i++) {
        for(j=i+2;j<=max;j++) {
           for(k=i+1;k<j;k++) {
               if(s.count(k)!=1) {
                   continue;
               } else {
                   if((dude[i].first + dude[j].first)/2 == dude[k].first && (dude[i].second + dude[j].second)/2 == dude[k].second);
                   sum++;
               }
           }
        }
    }
    printf("%d\n",sum);
    return 0;
}