#include <bits/stdc++.h>
using namespace std;

int main() {
	// your code goes here
	int n;
	cin>>n;
	vector<int> a(n);
	for(int i = 0; i < n; i++){
		cin>>a[i];
	}
	
	int sum = 0, start = 0, end = n-1;
	int p1 = 0, p2 = 0, curr_ele = 0,turn=0;
	bool reversed = false;
	while(start <= end){
		curr_ele = 0;
		if(turn % 2 == 0){
			if(reversed == false){
				p1 = p1 + a[start];
				curr_ele = a[start];
				start++;
			}
			else{
				p1 = p1 + a[end];
				curr_ele = a[end];
				end--;
			}
		}
		else{
			if(reversed == false){
				p2 = p2 + a[start];
				curr_ele = a[start];
				start++;
			}
			else{
				p2 = p2 + a[end];
				curr_ele = a[end];
				end--;
			}
		}
		
		if(curr_ele % 2 == 0){
			reversed = !reversed;
		}
		turn++;
	}
	cout<<p1 - p2<<endl;
	return 0;
}