#include<algorithm>
#include<cstdio>
#include<cstring>
#include<map>
#include<cmath>
#define LL long long
using namespace std;

const int N = 100;
const int H = 1007;

struct Point
{
    int x,y;
};

Point p[N];

struct Node
{
    int x,y;
    int next;
};

Node node[N];
int cur,n;
LL ans;

int vis[H];



void Insert(int x,int y)
{
    int h = (x * x + y * y) % H;
    node[cur].x = x;
    node[cur].y = y;
    node[cur].next = vis[h];
    vis[h] = cur++;
}

bool ok(int x,int y)
{
    int h = (x * x + y * y) % H;
    int t = vis[h];
    while(t != -1)
    {
        if(x == node[t].x && y == node[t].y) return true;
        t = node[t].next;
    }
    return false;
}

void solve()
{
    for(int i=0;i<n;i++)
    {
        scanf("%d%d",&p[i].x,&p[i].y);
        Insert(p[i].x,p[i].y);
    }
    for(int i=0;i<n;i++)
    {
        for(int j=i+1;j<n;j++)
        {
            int x1 = p[i].x - (p[i].y - p[j].y);
            int y1 = p[i].y + (p[i].x - p[j].x);
            int x2 = p[j].x - (p[i].y - p[j].y);
            int y2 = p[j].y + (p[i].x - p[j].x);
            if(ok(x1,y1) && ok(x2,y2)) ans++;
        }
    }
    for(int i=0;i<n;i++)
    {
        for(int j=i+1;j<n;j++)
        {
            int x1 = p[i].x + (p[i].y - p[j].y);
            int y1 = p[i].y - (p[i].x - p[j].x);
            int x2 = p[j].x + (p[i].y - p[j].y);
            int y2 = p[j].y - (p[i].x - p[j].x);
            if(ok(x1,y1) && ok(x2,y2)) ans++;
        }
    }
    ans >>= 2;
}

int main()
{
    while(scanf("%d",&n)!=EOF)
    {
        if(n<=3)
        {
            printf("0\n");
            continue;
        }
        for(int i=0;i<H;i++)
            vis[i]=-1;
        cur = ans = 0;
        solve();
        printf("%I64d\n",ans);
    }

    return 0;
}