#include<iostream>

int main() {
	long long height, width, people, k;

	std::cin >> height >> width >> people >> k;

	long long result = (height * width) % people;
	if (result == 0) {
		std::cout << (k == people ? "YES" : "NO") << std::endl;
	}
	else {
		std::cout << (result == k ? "YES" : "NO") << std::endl;
	}

	return 0;
}