use proconio::input;

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

    let mut a_sum = 0;
    let mut b_sum = 0;
    for &(a, b) in &ab {
        a_sum += a;
        b_sum += b;
    }

    let mut ans = 0usize;
    for &(a, b) in &ab {
        a_sum -= a;
        b_sum -= b;
        ans += (a * b_sum).max(b * a_sum);
    }

    println!("{ans}");
}