#include <bits/stdc++.h>
//#include <atcoder/modint>

using namespace std;
//using namespace atcoder;
using ll = long long;
//using mint = modint998244353;

int main(){
    cin.tie(nullptr);
    ios_base::sync_with_stdio(false);

    ll N, mi=1e9, mx=-1e9, A, S=0;
    cin >> N;
    for (int i=0; i<N; i++){
        cin >> A;
        mi = min(mi, A);
        mx = max(mx, A);
    }

    if (mi > 0) cout << mx * 2 << endl;
    else if (mx < 0) cout << -mi * 2 << endl;
    else cout << (mx-mi) * 2 << endl;

    return 0;
}