#include <bits/stdc++.h>
using namespace std;

int main()
{
    int N;
    cin >> N;
    int Max_minus = -1e9;
    int Max_plus = -1e9;
    for (int i = 0; i < N; i++)
    {
        int A;
        cin >> A;
        if (A >= 0)
        {
            Max_plus = max(Max_plus, A);
        }
        else
        {
            Max_minus = max(Max_minus, abs(A));
        }
    }
    cout << Max_minus * 2 + Max_plus * 2;
}