#include <iostream>
#include <vector>
#include <algorithm>
#include <set>

using namespace std;

int main()
{
    int n;
    cin >> n;
    vector<vector<long long>> dp(n + 1, vector<long long> (n + 1, -1e18));
    vector<int> a(n), b(n);
    for (int i = 0; i < n; ++i) cin >> a[i] >> b[i];
    reverse(a.begin(), a.end());
    reverse(b.begin(), b.end());
    dp[0][0] = 0;
    for (int i = 0; i < n; ++i)
    {
        for (int j = 0; j < n; ++j) dp[i + 1][j + 1] = max(dp[i + 1][j + 1], dp[i][j] + b[i]);
        for (int j = 0; j <= n; ++j)
        {
            dp[i + 1][j] = max(dp[i + 1][j], dp[i][j] + (long long)a[i] * j);
        }
    }
    long long ans = 0;
    for (int i = 0; i <= n; ++i) ans = max(ans, dp[n][i]);
    cout << ans << endl;
}