#include <bits/stdc++.h>
using namespace std;
                                    
                                    
int main()
{   
    int A,B,C,D;
    int S;
    cin >>A>>B>>C>>D>>S;
    if (A*C+B*D<=S)
    {
        cout << "Yes";
    }
    else
    {
        cout << "No";
    }
    return 0;
}