using System;
using System.Linq;

class No512{
    static void Main(){
        var speed=Console.ReadLine().Split(' ').Select(x=>Int32.Parse(x)).ToArray();
        var count=Int32.Parse(Console.ReadLine());
        var distance=Console.ReadLine().Split(' ').Select(x=>Int32.Parse(x)).ToArray();
        var ans="YES";
        for(int i=1;i<count;++i){
            if(distance[i-1]*100/speed[0]>distance[i]*100/speed[1]){
                ans="NO";
                break;
            }
        }
        Console.WriteLine(ans);
    }
}