H, W, N, K = input().split()
H, W, N, K = int(H), int(W), int(N), int(K)

mod = (H*W) % N
if mod == 0 and K == N:
    print("YES")
elif mod == 0 and K != N:
    print("NO")
elif mod == K:
    print("YES")
else:
    print("NO")