use std::u64;

use proconio::input;

fn solve() -> u64 {
  input! {
    n: usize,
    ab: [(i64, i64); n],
  }
  let mut table = vec![i64::MIN; n + 1];
  table[0] = 0;
  for &(ai, bi) in ab.iter() {
    let mut ntable = vec![i64::MIN; n + 1];
    let mut atable = table.clone();
    for i in 1..=n {
      atable[i] = atable[i-1].max(atable[i]);
    }
    for i in 0..=n {
      ntable[i.saturating_sub(1)] = table[i] + bi;
    }
    for i in 0..=n {
      ntable[i] = ntable[i].max(atable[i] + ai * i as i64);
    }
    table = ntable;
  }
  table[0] as u64
}

fn main() {
  let ans = solve();
  println!("{}", ans);
}