import java.util.*;

public class Skg {
    
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);

        int A = sc.nextInt();
        int B = sc.nextInt();
        int C = sc.nextInt();
        int D = sc.nextInt();

        int S = sc.nextInt();

        if(S >= A*C + B*D){
            System.out.println("Yes");
        }else{
            System.err.println("No");
        }

        sc.close();
    }
    
}