#include <bits/stdc++.h>
#include<iostream>
#include<map>
#include<vector>
#include <algorithm>
#include<math.h>
#include <iomanip>
#include<set>
#include <numeric>
#include<string>
using ll = long long;
using namespace std;


int main()
{
    ll n, dif, min1 = 0, sum1 = 0;
    cin >> n;
    vector<int> a(2*n+1);
    for (int i = 1; i <= 2*n; i++){
        cin >> a[i];
        if (!(i%2)) sum1 += a[i-1]*a[i];
    }
    for (int i = 1; i < 2*n; i++){
        for (int j = i+1; j <= 2*n; j++){
            if ((i%2) && (j == i+1)) continue;
            if (!(i%2) && !(j%2)) dif = (a[i-1] * a[i] + a[j-1]*a[j]) - (a[i-1]*a[j] + a[j-1]*a[i]);
            else if (!(i%2) && (j%2)) dif = (a[i-1] * a[i] + a[j]*a[j+1]) - (a[i-1]*a[j] + a[i]*a[j+1]);
            else if ((i%2) && !(j%2)) dif = (a[i] * a[i+1] + a[j-1]*a[j]) - (a[j]*a[i+1] + a[j-1]*a[i]);
            else dif = (a[i] * a[i+1] + a[j]*a[j+1]) - (a[j]*a[i+1] + a[i]*a[j+1]);
            if (min1 > dif) min1 = dif;
        }
    }
    cout << sum1 - min1 << endl;
}