#include <bits/stdc++.h>
using namespace std;
using ll = long long;

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	int a, b, c, d, s;
	cin >> a >> b >> c >> d >> s;
	cout << (a * c + b * d <= s ? "Yes" : "No") << '\n';
}