fn solve(scanner: &mut Scanner) {
    let n: usize = scanner.next();
    let mut sum_a: usize = 0;
    let mut sum_b: usize = 0;
    let ab_list: Vec<(usize, usize)> = (0..n)
        .map(|_| {
            let a = scanner.next();
            let b = scanner.next();
            sum_a += a;
            sum_b += b;
            (a, b)
        })
        .collect();
    let mut ans: usize = 0;
    for &(a, b) in ab_list.iter() {
        sum_a -= a;
        sum_b -= b;
        ans += (a * sum_b).max(b * sum_a);
    }
    println!("{}", ans);
}

fn main() {
    let mut scanner = Scanner::new();
    let t: usize = 1;
    for _ in 0..t {
        solve(&mut scanner);
    }
}

pub struct Scanner {
    buf: Vec<String>,
}

impl Scanner {
    fn new() -> Self {
        Self { buf: vec![] }
    }

    fn next<T: std::str::FromStr>(&mut self) -> T {
        loop {
            if let Some(x) = self.buf.pop() {
                return x.parse().ok().expect("");
            }
            let mut source = String::new();
            std::io::stdin().read_line(&mut source).expect("");
            self.buf = Self::split(source);
        }
    }

    fn split(source: String) -> Vec<String> {
        source
            .split_whitespace()
            .rev()
            .map(String::from)
            .collect::<Vec<_>>()
    }
}