#include <stdio.h>
#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf 1000000001

long long get(deque<long long> c,bool f0,bool f1){
	long long a=0,b=0;
	
	while(c.size()!=0){
		if(f0){
			a += c.back();
			c.pop_back();
		}
		else{
			a += c.front();
			c.pop_front();
		}
		if(c.size()==0)break;
		if(f1){
			b += c.back();
			c.pop_back();
		}
		else{
			b += c.front();
			c.pop_front();
		}
	}
	a = abs(a);
	b = abs(b);
	return a-b;
}

int main(){
	int N;
	cin>>N;
	deque<long long> c(N);
	
	rep(i,N){
		cin>>c[i];
	}
	
	sort(c.begin(),c.end());
	
	long long ans = max(min(get(c,true,false),get(c,true,true)),min(get(c,false,false),get(c,false,true)));
	
	cout<<ans<<endl;
	
	return 0;
}