import sys, math
 
sys.setrecursionlimit(10 ** 6)
stdin = sys.stdin

ni = lambda: int(ns())
na = lambda: list(map(int, stdin.readline().split()))
ns = lambda: stdin.readline().strip()
nsa = lambda: list(stdin.readline().split())
mod = 10 * 7 + 7

h, w, n, k = na()

num = h * w

if num % n == k or (k == n and num % n == 0):
    print('YES')
else:
    print('NO')