#include<cstdio>
#include<vector>
#include<algorithm>
#include<cstring>
using namespace std;
const long long NMAX = 1005;
const long long BASE = 103;
const long long MOD = 100009;
long long N,M,i,j,r,X0,Y0,X1,Y1,X2,Y2,X3,Y3,dx,dy,mijx,mijy,SOL,ok;
struct Point {long long x,y;} P[NMAX]; char S[100];
vector<pair<int,int> > V[MOD];
int main()
{
    freopen("patrate3.in","r",stdin);
    freopen("patrate3.out","w",stdout);
    scanf("%d",&N);
    for(i=1;i<=N;i++)
    {
        scanf("%s",S+1); M=strlen(S+1);
        for(j=1;j<=M;j++) if(S[j]>='0' && S[j]<='9') P[i].x=P[i].x*10+S[j]-'0';
        if(S[1]=='-') P[i].x*=-1;

        scanf("%s",S+1); M=strlen(S+1);
        for(j=1;j<=M;j++) if(S[j]>='0' && S[j]<='9') P[i].y=P[i].y*10+S[j]-'0';
        if(S[1]=='-') P[i].y*=-1;

        P[i].x*=2; P[i].y*=2;

        r=(1LL*BASE*(abs(P[i].x))+(abs(P[i].y)))%MOD;
        V[r].push_back(make_pair(P[i].x,P[i].y));
    }
    for(i=1;i<N;i++)
        for(j=1;j<=N;j++)
            if(P[i].y<P[j].y)
            {
                X0=P[i].x; Y0=P[i].y;
                X1=P[j].x; Y1=P[j].y;
                mijx=X0+(X1-X0)/2;
                mijy=Y0+(Y1-Y0)/2;
                dx=abs(mijx-X0);
                dy=abs(mijy-Y0);
                X2=mijx+dy; Y2=mijy-dx;
                X3=mijx-dy; Y3=mijy+dx;

                r=(1LL*BASE*(abs(X2))+abs(Y2))%MOD; ok=0;
                for(vector<pair<int,int> >::iterator it=V[r].begin();it!=V[r].end();it++)
                    if(it->first==X2 && it->second==Y2) {ok=1; break;}
                if(!ok) continue;

                r=(1LL*BASE*(abs(X3))+abs(Y3))%MOD; ok=0;
                for(vector<pair<int,int> >::iterator it=V[r].begin();it!=V[r].end();it++)
                    if(it->first==X3 && it->second==Y3) {ok=1; break;}
                if(!ok) continue;

                SOL++;
            }
    printf("%lld\n",SOL);
    return 0;
}