#coding: UTF-8

import sys
import re
import itertools
from math import log
from collections import deque

### defs ###


### main ###
H,W,N,K = map(int,sys.stdin.readline().split())
m = H*W%N
if(m==0):
	m=N
if (m==K):
	print("YES")
else:
	print("NO")