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

int32_t main(){

    int a, b, c, d, s;
    cin >> a >> b >> c >> d >> s;
    if(a*c + b*d <= s){
        cout << "Yes" << endl;
    }
    else{
        cout << "No" << endl;
    }
    return 0;
}