#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (ll i = 0; i < (ll)(n); i++)
#define all(x) (x).begin(), (x).end()
using ll = long long;
const ll MOD = 998244353;
#include<atcoder/all>
using namespace atcoder;
using mint = modint998244353;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  ll n;cin>>n;
  vector<ll> A(n);
  rep(i,n)cin>>A[i];
  sort(all(A));
  ll ans=0;
  rep(i,n-1){
    if(A[i]<0&&A[i+1]<0){
      ans+=-(A[i]+A[i+1]);
    }else{
      ans+=A[i+1]-A[i];
    }
  }
  if(A[1]<0&&(-A[1]>A[n-1])){
    ans-=-A[1]-A[n-1];
  }
  cout<<ans<<endl;
}