#!/usr/bin/perl

use warnings;
use strict;

my ($h, $w, $n, $k) = split / /, <>;
my $sum = $h * $w;


if(($sum == $n)and($n == $k)) {
	print "YES\n";
} elsif($sum % $n == $k) {
	print "YES\n";
} elsif(($sum == $n)and($k == 1)) {
	print "NO\n";
} elsif(($sum % $n == 0)and($sum % $k == 0)) {
	print "YES\n";
} else {
	print "NO\n";
}

exit;