#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<ll> dp(n + 1);
    for(int i = 0; i < n; i++){
        vector<ll> ndp(n - i);
        ll a, b;
        cin >> a >> b;
        for(int j = 0; j <= n - i; j++){
            if(j < n - i)ndp[j] = max(ndp[j], dp[j] + j * a);
            if(j >= 1) ndp[j - 1] = max(ndp[j - 1], dp[j] + b);
        }
        swap(dp, ndp);
    }
    cout << dp[0] << '\n';
}