package m.shin; import java.util.Scanner; public class Con512 { public static void main(String[] args) { Scanner s = new Scanner(System.in); double x = s.nextDouble() * 50 / 3 , y = s.nextDouble() * 50 / 3; int n = s.nextInt(); double[] a = new double[n]; for(int i = 0;i < n;i++){ a[i] = s.nextDouble(); } s.close(); boolean ft = true; for(int i = 0;i < n-1;i++){ if(a[i] / x > a[i+1] / y){ System.out.println("NO"); ft = false; break; } } if(ft){ System.out.println("YES"); } } }