import math
import sys
def S(): return sys.stdin.readline().rstrip()
def I(): return int(sys.stdin.readline().rstrip())
def MI(): return map(int, sys.stdin.readline().rstrip().split())
def LI(): return list(map(int, sys.stdin.readline().rstrip().split()))
def LS(): return list(sys.stdin.readline().rstrip().split())

h, w, n, k = MI()
if (h*w)%n == k:
    print("YES")
elif n == k and (h*w)%n == 0:
    print("YES")
else:
    print("NO")