use proconio::input;

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

fn solve() -> i64 {
    input! {
        n: usize,
        cc: [i64; n],
    }

    let min_c = *cc.iter().min().unwrap();
    let max_c = *cc.iter().max().unwrap();

    if min_c >= 0 {
        return 2 * max_c;
    }

    if max_c <= 0 {
        return -2 * min_c;
    }

    2 * (max_c - min_c)
}