use proconio::input;

fn main() {
    input! {
        n: usize,
        ab: [(i64,i64); n],
    }

    let mut dp = vec![vec![-1; n + 1]; n + 1];
    dp[n][0] = 0;
    for i in (1..=n).rev() {
        for count in 0..n {
            if dp[i][count] < 0 {
                continue;
            }
            dp[i - 1][count + 1] = dp[i - 1][count + 1].max(dp[i][count] + ab[i - 1].1);
            dp[i - 1][count] = dp[i - 1][count].max(dp[i][count] + count as i64 * ab[i - 1].0);
        }
    }

    println!("{}", dp[0].iter().max().unwrap());
}