#![allow(unused_imports)]

fn main() {
    input! {
        n: usize,
        c: [(u64, u64); n],
    }
    let mut dp = mvec![0; (n+1, n+1)];
    for i in 0..n {
        for j in 0..=n {
            chmax!(dp[i + 1][j], dp[i][j] + c[i].0 * j as u64);
            if j > 0 {
                chmax!(dp[i + 1][j - 1], dp[i][j] + c[i].1);
            }
        }
    }
    println!("{}", dp[n][0]);
}

use proconio::{input, marker::*};
use std::{cmp::Reverse, collections::*};

#[macro_export]
macro_rules! chmax {
    ($a:expr, $b:expr) => {{
        let tmp = $b;
        if $a < tmp {
            $a = tmp;
            true
        } else {
            false
        }
    }};
}

#[macro_export]
macro_rules! chmin {
    ($a:expr, $b:expr) => {{
        let tmp = $b;
        if $a > tmp {
            $a = tmp;
            true
        } else {
            false
        }
    }};
}

#[macro_export]
/// mvec![]
macro_rules! mvec {
    ($val:expr; ()) => {
        $val
    };
    ($val:expr; ($size:expr $(,$rest:expr)*)) => {
        vec![mvec![$val; ($($rest),*)]; $size]
    };
}