#include <bits/stdc++.h>

#include <atcoder/all>
using namespace std;
using i32 = int;
using u32 = unsigned int;
using i64 = long long;
using u64 = unsigned long long;
#define FAST_IO                \
  ios::sync_with_stdio(false); \
  cin.tie(0);
const i64 INF = 1001001001001001001;
using Modint = atcoder::static_modint<998244353>;

int main() {
  FAST_IO
  auto ans = 0LL;

  int N;
  cin >> N;
  vector<i64> c(N);
  for (auto& x : c) cin >> x;

  i64 mx = ranges::max(c);
  i64 mn = ranges::min(c);

  if (mx > 0 && mn < 0) {
    ans = (abs(mx) + abs(mn)) * 2;
  } else {
    ans = max(abs(mx), abs(mn)) * 2;
  }

  cout << ans << endl;
}