695 B | 695 chars
#include <bits/stdc++.h>
using namespace std;
typedef unsigned long long ull;
typedef long long ll;
typedef vector <ll> llv1;
typedef unsigned int uint;
typedef vector <ull> ullv1;
typedef vector <vector <ull>> ullv2;
ll N,X[110],Y[110],ans;
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin >> N;
for(int i=0; i<N; i++) cin >> X[i] >> Y[i];
for(int i=0; i <N; i++)
for(int j =0; j <N; j++)
for(int k = 0; k<N; k++)
if(i!=j && j!=k && i!=k)
if(X[i] == X[j] && Y[j] == Y[k]) {
ans = max(ans,abs(Y[j]-Y[i]) * abs(X[j]-X[k]));
}
cout << ans;
}