#include <bits/stdc++.h>
#pragma GCC optimize("unroll-loops,no-stack-protector")
#pragma GCC target("sse,sse2,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#define watch(x) cout <<(#x)<<" is "<<(x)<<endl
#define debug cout <<"hi"<<endl
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
const int MOD=1e9+7;
const int INF32=1<<30;
const ll INF64=1LL<<60;

void solve(){
  int n; cin >>n;
  ll a[n],cnt=0,sum=0,mn=MOD;
  for(int i=0; i<n; i++){
    ll x; cin >>x; a[i]=x;
    if(x<=0) cnt++;
    mn=min(mn,abs(x));
    sum+=abs(x);
  }
  if(cnt%2) sum-=2*mn;
  cout <<sum;
}

int main(){
  ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
  solve();
return 0;}
#include <iostream>
using namespace std;
typedef long long int LLI;
int main()
{
	int n;
	LLI a, b, x, diff, sum = 0 ;
	cin >> n >> x;
	cin >> a >> b;
	if( a + b > x )
	{
		diff = a + b - x;
		if( diff <= b )
	    	b -= diff;
	    else
	    	b = 0;
		sum += diff;
	}
	a = b;
	for(int i = 2; i < n; i++)
	{
	    cin >> b;
	    if( a + b > x )
		{
			diff = a + b - x;
			if( diff <= b )
		    	b -= diff;
		    else
		    	b = 0;
			sum += diff;
		}
		a = b;
	}
	cout << sum;
}
    