#include<cstdio>
#include<iostream>
#include<cstring>
#include<iomanip>
#include<set>
#include<ctime>
#include<vector>
#include<queue>
#include<map>
#include<algorithm>
using namespace std;
struct node{
    int x,y;
};
bool cmp(node a,node b)
{
    if (a.x!=b.x)
        return a.x<b.x;
    return a.y<b.y;
}
int dis(node a, node b)
{
    return (a.x - b.x)*(a.x - b.x) + (a.y-b.y)*(a.y-b.y);
}
int main()
{
//    freopen("D://input.txt","r",stdin);
//    freopen("D://output.txt", "w", stdout);
    int n;
    int pic[10][10];
    while (scanf("%d", &n) != EOF)
    {
        memset(pic,0,sizeof(pic));
        node a[21];
        int i,j,k,l;
        for (i = 0; i < n; i++)
        {
            scanf("%d%d",&a[i].x,&a[i].y);
            pic[a[i].x][a[i].y]++;
        }
        sort(a,a+n,cmp);
        int ans=0;
        for (i = 0; i < n; i++)
        {
            for (j = i + 1; j < n; j++)
            {
                for (k = j + 1; k < n; k++)
                {
                    for (l = k + 1; l < n; l++)
                    {
                        if (dis(a[i], a[j]) == dis(a[i], a[k]) && dis(a[k], a[l]) == dis(a[l], a[j]) && dis(a[k], a[l]) == dis(a[i], a[j]) && dis(a[k], a[i]) == dis(a[l], a[k]) && dis(a[i], a[l]) == dis(a[k], a[j]))
                        {
                            ans++;
                            continue;
                        }
                        if (dis(a[i], a[l]) == dis(a[i], a[k]) && dis(a[k], a[j]) == dis(a[l], a[j]) && dis(a[i], a[l]) == dis(a[l], a[j]) && dis(a[k], a[i]) == dis(a[k], a[j]) && dis(a[i], a[j]) == dis(a[k], a[l]))
                        {
                            ans++;
                            continue;
                        }
                        if (dis(a[i], a[l]) == dis(a[i], a[j]) && dis(a[k], a[j]) == dis(a[l], a[k]) && dis(a[k], a[j]) == dis(a[i], a[j]) && dis(a[i], a[l]) == dis(a[l], a[k]) && dis(a[l], a[j]) == dis(a[k], a[i]))
                        {
                            ans++;
                            continue;
                        }
                    }
                }
            }
        }
        printf("%d\n",ans);
    }
//    printf("%.6lf\n",(double)clock()/CLOCKS_PER_SEC);
    return 0;
}