#include<bits/stdc++.h>
using namespace std;
#define rep(i,N) for(i=0;i<N;i++)
#define ll long long

int main(void){
    ll N;
    ll C[100009];

    ll i,j,k;

    cin>>N;
    rep(i,N)cin>>C[i];

    sort(C,C+N);

    ll ans=0;
    if(C[0]<0)ans+=abs(C[0]);
    if(C[N-1]>0)ans+=C[N-1];

    cout<<2*ans<<endl;

    return 0;
}