use std::{
    process::exit,
    collections::{
        HashSet,
        HashMap,
    },
};
use proconio::{
    input,
    marker::Chars,
};
// use itertools::*;

fn yes_no(cdt: bool) {
    println!("{}", if cdt { "Yes" } else { "No" })
}

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

    if n == 1 {
        println!("{}", c[0].abs()*2);
    }

    let (mut l, mut r): (isize, isize) = (c[0], c[1]);

    for i in 0..n {
        if c[i] < l {
            l = c[i];
        } else if r < c[i] {
            r = c[i];
        }
    }

    println!("{}", if r <= 0 {
        2*l.abs()
    } else if 0 <= l {
        2*r.abs()
    } else {
        2*(l.abs() + r.abs())
    });
}