#include <fstream>
#include <set>
#include <cstring>
#define H(x,y) (x*1e9+y)
#define Ref &
using namespace std;

ifstream in ("patrate3.in");
ofstream out ("patrate3.out");

const int NMax=1005;
pair <int,int> Puncte[NMax];
set<long long> Setu;
string buff;

bool Solve(int arg1,int arg2)
{
    long long x1=Puncte[arg1].first;
    long long y1=Puncte[arg1].second;
    long long x2=Puncte[arg2].first;
    long long y2=Puncte[arg2].second;

    long long dx=x2-x1;
    long long dy=y1-y2;
    long z1=x1+dy,t1=y1+dx;
    long z2=x2+dy,t2=y2+dx;
    return ((Setu.find(H(z1, t1))!= Setu.end()) && (Setu.find(H(z2, t2)) != Setu.end()));
}
void Carol_Cel_Mare(long long Ref x)//cica asta e Read
{
    int pos=0;
    bool s=false;
    x=0;
    in>>buff;
    if (buff[pos]=='-')
    {
        s=1;
        pos++;
    }
    while ((unsigned)pos<buff.length())
    {
        if (buff[pos]>='0'&&buff[pos]<='9')
        {
            x=x*10+buff[pos]-'0';
        }
        pos++;
    }
    if(s)
        x=-x;
}
int main()
{
    long long n,ans,finc,sjn;
    in>>n;
    //finc e x
    //sjn e y
    for (int i=1;i<=n;i++)
    {
        Carol_Cel_Mare(finc);
        Carol_Cel_Mare(sjn);
        Puncte[i]=make_pair(finc,sjn);
        Setu.insert(H(finc,sjn));
    }
    ans=0;
    for (int i=1;i<=n;i++)
    {
        for (int j=i+1;j<=n;j++)
        {
            ans+=Solve(i,j);
            ans+=Solve(j,i);
        }
    }
    out<<ans/4;
    return 0;
}