Untitled

#include <iostream>
using namespace std;

int main()
{
	int a, b;
	cin >> a >> b;
	if (a % 2 == 0 and a > 0 and a > -100 and a < 100 and b % 2 != 0 and b < 0 and b > -100 and b < 100) {
		cout << a - b;
	}
	if (a % 2 != 0 and a < 0 and a > -100 and a < 100 and b % 2 == 0 and b > 0 and b > -100 and b < 100) {
		cout << b - a;
	}
	if ((a % 2 != 0 and b % 2 != 0) or (a % 2 == 0 and b % 2 == 0) or (a > 0 and b > 0) or (a < 0 and b < 0) or (a < -100 or a > 100) or (b < -100 or b > 100) or (a % 2 == 0 and a < 0) or (a % 2 != 0 and a > 0) or (b % 2 == 0 and b < 0) or (b % 2 != 0 and b > 0)) {
		cout << "NO";
	}
}