use proconio::input;

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

    let min_x:isize = *c.iter().min().unwrap();
    let max_x:isize = *c.iter().max().unwrap();
    
    let mut ans:usize = 2*(max_x - min_x) as usize;

    if min_x > 0 {
        ans += min_x as usize;
    } else if max_x < 0 {
        ans -= max_x as usize;
    }
    
    if c.len()==1 {
        ans = 2*min_x.abs() as usize;
    }

    println!("{}", ans);
}