import java.util.Scanner;

public class Solution{

    public static void main(String[] args) {

        Scanner entrada = new Scanner(System.in);

        int a = entrada.nextInt();
        int b = entrada.nextInt();
        int c = entrada.nextInt();
        int d = entrada.nextInt();
        int e = entrada.nextInt();

        if((a * c) + (b*d) <= e){
            System.out.println("Yes");
        }else{
            System.out.println("No");
        }
    }
}