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

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int a,b,c,d,s; cin >> a >> b >> c >> d >> s;
    if(a*c+b*d <= s) cout << "Yes\n";
    else cout << "No\n";
}