#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

int main() {
    ll n;
    cin >> n;
    ll c[n];
    for (int i = 0; i < n; i++) {
        cin >> c[i];
    }

    ll min_v = LLONG_MAX, max_v = LLONG_MIN;
    for (int i = 0; i < n; i++) {
        min_v = min(min_v, c[i]);
        max_v = max(max_v, c[i]);
    }

    ll ans = 0;
    if (min_v < 0) {
        ans += -min_v*2;
    }
    if (0 < max_v) {
        ans += max_v*2;
    }

    cout << ans << endl;

    return 0;
}