#!/usr/bin/env python3
#fileencoding: utf-8

H, W, N, K = [int(i) for i in input().strip().split(" ")]

last = (H*W) % N

if K == N:
    if last == 0:
        print("YES")
    else:
        print("NO")
else:
    if last == K:
        print("YES")
    else:
        print("NO")