#include <bits/stdc++.h>
using namespace std;
using ll = long long;

int main(){
	ios::sync_with_stdio(false);
    cin.tie(0);
    int N;
    cin >> N;
    vector<pair<ll,ll>> a(N);
    ll s1 = 0, s2 = 0;
    for(int i = 0; i < N; i++){
        cin >> a[i].first >> a[i].second;
        s1 += a[i].first, s2 += a[i].second;
    }
    ll ans = 0;
    for(int i = 0; i < N; i++){
        s1 -= a[i].first, s2 -= a[i].second;
        if(s1 * a[i].second > s2 * a[i].first){
            ans += s1 * a[i].second;
        }else{
            ans += s2 * a[i].first;
        }
    }
    cout << ans << '\n';
}