#include<stdio.h>

 #include<algorithm>

 #include<vector>

 using namespace std;

 #define mod 10007

 struct point

 {

     int x,y;

 }x[];

 vector<point>hash[mod];

 void insert(int a)

 {

     int h=(x[a].x*x[a].x+x[a].y*x[a].y)%mod;

     hash[h].push_back(x[a]);

 }

 bool cmp(point a,point b)

 {

     if(a.x==b.x)

         return a.y<b.y;

     return a.x<b.x;

 }

 bool search(int a,int b)

 {

     int h=(a*a+b*b)%mod;

     for(int i=;i<hash[h].size();i++)

     {

         if(hash[h][i].x==a&&hash[h][i].y==b)

         return true;

     }

     return false;

 }

 int main()

 {

     int n;

     while(scanf("%d",&n)!=EOF&&n)

     {

         for(int i=;i<mod;i++)

             hash[i].clear();

         for(int i=;i<=n;i++)

         {

             scanf("%d%d",&x[i].x,&x[i].y);

             insert(i);

         }

         int cnt=;

         sort(x+,x+n+,cmp);

         for(int i=;i<=n;i++)

         {

             for(int j=i+;j<=n;j++)

             {

                 int x1,y1,x2,y2;

                 x1=x[i].x-(x[j].y-x[i].y);

                 y1=x[i].y+(x[j].x-x[i].x);

                 x2=x[j].x-(x[j].y-x[i].y);

                 y2=x[j].y+(x[j].x-x[i].x);

                 if(search(x1,y1)&&search(x2,y2))

                     cnt++;

             }

         }

         printf("%d\n",cnt/);

     }

     return ;

 }