#include<iostream>
#include<cmath>
using namespace std;

double hitungGradien(int y2, int y1, int x2, int x1){
    return (double) (y2-y1) / (x2-x1);
}

int main(){
    int N;
    int x[2500];
    int y[2500];
    int numberOfGradient;
    double m[2500];
    int count;

    cin>>N;
    for(int i=0; i<N; i++){
        cin>>x[i]>>y[i];
    }

    cout<<endl;

    numberOfGradient = 0;
    for(int i=0; i<N; i++){
        for(int j=N-1; j>i; j--){
            //cout<<x[i]<<","<<y[i]<<endl;
            //cout<<x[j]<<","<<y[j]<<endl;
            m[numberOfGradient] = abs(hitungGradien(y[j],y[i],x[j],x[i]));
            numberOfGradient++;
        }
    }

    //cout<<numberOfGradient;


    for(int k=0; k<numberOfGradient; k++){
        cout<<k<<" = "<<m[k]<<endl;
    }

    return 0;
}