#include <iostream>
#include <string>
#include <algorithm>
#include <functional>
#include <vector>
#include <stack>
#include <queue>
#include <set>
#include <map>
#include <tuple>
#include <cstdio>
#include <cassert>
#include <atcoder/modint>
#define rep(i, n) for(i = 0; i < n; i++)
#define int long long
using namespace std;
using namespace atcoder;

int INF = 1e+18;
int n;
int a[5000], b[5000];
int dp[5001][5001];

signed main() {
    int i, j;

    cin >> n;
    rep(i, n) cin >> a[i] >> b[i];

    rep(i, n + 1) rep(j, n + 1) dp[i][j] = -INF;
    rep(i, n + 1) dp[0][i] = 0;

    rep(i, n) {
        for (j = 0; j <= n - i; j++) {
            if (dp[i][j] == -INF) continue;
            dp[i + 1][j] = max(dp[i + 1][j], dp[i][j] + j * a[i]);
            dp[i + 1][j - 1] = max(dp[i + 1][j - 1], dp[i][j] + b[i]);
        }
    }

    cout << dp[n][0] << endl;
    return 0;
}