fn read<T: std::str::FromStr>() -> T {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).ok();
    s.trim().parse().ok().unwrap()
}

fn read_vec<T: std::str::FromStr>() -> Vec<T> {
    read::<String>()
        .split_whitespace()
        .map(|e| e.parse().ok().unwrap())
        .collect()
}

fn argsort<T: std::cmp::Ord + std::marker::Copy>(v: &Vec<T>) -> Vec<usize> {
    let mut sort_v = Vec::new();
    for i in 0..v.len() {
        sort_v.push((v[i], i));
    }
    sort_v.sort();
    sort_v.iter().map(|x| x.1).collect::<Vec<usize>>()
}

fn main() {
    let n = read::<usize>();
    let mut a = vec![0; n];
    let mut b = vec![0; n];
    for i in 0..n {
        let v = read_vec::<i64>();
        a[i] = v[0];
        b[i] = v[1];
    }
    let mut base_a = Vec::new();
    let mut base_b = Vec::new();
    for i in 0..n {
        base_a.push(a[i] + b[i]);
        base_b.push(b[i] + a[i]);
    }

    let mut a_index = argsort(&base_a);
    let mut b_index = argsort(&base_b);
    let mut used_candidate = std::collections::HashSet::new();

    let mut ans = 0i64;
    for i in 0..n / 2 {
        let mut a_candidate;
        loop {
            a_candidate = a_index[a_index.len() - 1];
            if !used_candidate.contains(&a_candidate) {
                break;
            } else {
                a_index.pop();
            }
        }
        let mut b_candidate;
        loop {
            b_candidate = b_index[b_index.len() - 1];
            if !used_candidate.contains(&b_candidate) {
                break;
            } else if a_candidate == b_candidate {
                continue;
            } else {
                b_index.pop();
            }
        }
        let plan_1_diff = a[a_candidate] - b[b_candidate];
        let plan_2_diff = a[b_candidate] - b[a_candidate];
        if plan_1_diff > plan_2_diff {
            ans += a[a_candidate];
            used_candidate.insert(a_candidate);
        } else {
            ans += a[b_candidate];
            used_candidate.insert(b_candidate);
        }

        let mut b_candidate;
        loop {
            b_candidate = b_index[b_index.len() - 1];
            if !used_candidate.contains(&b_candidate) {
                break;
            } else {
                b_index.pop();
            }
        }
        let mut a_candidate;
        loop {
            a_candidate = a_index[a_index.len() - 1];
            if !used_candidate.contains(&a_candidate) {
                break;
            } else if a_candidate == b_candidate {
                continue;
            } else {
                a_index.pop();
            }
        }
        let plan_1_diff = b[a_candidate] - a[b_candidate];
        let plan_2_diff = b[b_candidate] - a[a_candidate];
        if plan_1_diff > plan_2_diff {
            ans -= b[a_candidate];
            used_candidate.insert(a_candidate);
        } else {
            ans -= b[b_candidate];
            used_candidate.insert(b_candidate);
        }
    }
    if n % 2 == 1 {
        let mut a_candidate;
        loop {
            a_candidate = a_index.pop().unwrap();
            if !used_candidate.contains(&a_candidate) {
                used_candidate.insert(a_candidate);
                break;
            }
        }
        ans += a[a_candidate];
    }
    println!("{}", ans);
}


Measured memory_bytes: 18296