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

#define rep(i, n) for (int i = 0; i < (int)n; i++)

int main() {
  int n;
  cin >> n;
  vector<int> c(n);
  rep(i, n) cin >> c[i];
  sort(c.begin(), c.end());
  if (c[0] * c[n-1] > 0)
    cout << max(abs(c[0]), abs(c[n-1])) * 2;
  else
    cout << abs(c[0]) + abs(c[n-1]) + abs(c[0] - c[n-1]) << endl;
  return 0;
}