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

int main() {
    long long int n;
    cin >> n;
    vector<int> q;
    for(long long int i = 0; i<n; i++){
        long long int a;
        cin >>a;
        q.push_back(a);
    }
    sort(q.begin(), q.end());
    long long int mini = min(q[0],0);
    mini = abs(mini);
    if(q[n-1]>=0) cout << 2*(mini + q[n-1]) << endl;
    else cout << 2*mini << endl;
    
	// your code goes here

}