#include<bits/stdc++.h>

using namespace std;

#include<atcoder/all>
using namespace atcoder;
using mint=atcoder::modint998244353;

#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")

#define int long long

signed main(){
	int N;cin>>N;
	vector<int> C(N);for(auto&&e:C)cin>>e;
	C.push_back(0);
	sort(C.begin(),C.end());
	int mn=C[0],mx=C.back();

	cout<<(mx-mn)*2<<endl;
}