#include<cstdio>
#include<algorithm>
#define p(a,b) ((x[a]-x[b])*(x[a]-x[b])+(y[a]-y[b])*(y[a]-y[b]))
using namespace std;
int n,x[110],y[110],ans,i,j,k,l;
int main()
{
    while(scanf("%d",&n)!=EOF)
    {
        ans=0;
        for(i=1;i<=n;i++)
            scanf("%d%d",&x[i],&y[i]);
        for(i=1;i<=n;i++)
            for(j=1;j<=n;j++)if(j!=i)
                for(k=1;k<=n;k++)if(k!=i&&k!=j)
                    for(l=1;l<=n;l++)if(l!=i&&l!=j&&l!=k)
                        if(p(i,j)==p(j,k)&&p(i,j)==p(k,l)&&p(l,i)==p(i,j)&&p(i,k)==p(j,l))ans++;
        printf("%d\n",ans/8);
    }
}