#include<iostream>
#include<cmath>
using namespace std;
int main(){
    int n,x,y,z,t,S,a,b,c,d;
    cout<<"nhap n = "; cin>>n;
    S=0;
    for (int i=1;i<=n;i++)
    {
        cout<<"Hinh "<<i<<endl;
        cout<<"Toa do tam O"<<endl;
        cout<<" x = "; cin>>x;
        cout<<" y = ";cin>>y;
        cout<<"Toa do diem A"<<endl;
        cout<<" x = "; cin>>z;
        cout<<" y = ";cin>>t;

        if (sqrt(pow(x-z,2)+pow(y-t,2))>S)
        {
            S=sqrt(pow(x-z,2)+pow(y-t,2));
            a=x;b=y;c=z;d=t;
        }

    }
    cout<<"Duong tron lon nhat co tam O("<<a<<","<<b<<")"<<" va diem A("<<c<<","<<d<<")";


    }