package main

import (
	"fmt"
)

var (
	H, W, N, K int
)

func check() bool {
	tmp := (H * W) % N
	if tmp == 0 && N == K {
		return true
	}
	if tmp == K {
		return true
	}
	return false
}

func resolve() string {
	if check() {
		return "YES"
	}
	return "NO"
}

func main() {
	fmt.Scanf("%d %d %d %d\n", &H, &W, &N, &K)
	fmt.Println(resolve())
}