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

int main() {
	// your code goes here
	
	vector<int> arr = {3,6,2,3,5};
	
	int fr=0, sc=0;
	
	bool ch1 = true;
	bool rev=false;
	int n = arr.size();
	
	int i=n-1, j=0;
	
	while(j<=i){
		
		if(ch1){
			if(rev){
				fr+=arr[i];
				if(arr[i]%2==0) rev=!rev;
				i--;
			}
			else{
				fr+=arr[j];
				if(arr[j]%2==0) rev=!rev;
				j++;
			}
		}
		else{
			if(rev){
				sc+=arr[i];
				if(arr[i]%2==0) rev=!rev;
				i--;
			}
			else{
				sc+=arr[j];
				if(arr[j]%2==0) rev=!rev;
				j++;
			}
		}
		
		
		ch1 = !ch1;
	}
	
	cout<< fr-sc;
	return 0;
}