import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;

import static java.lang.System.in;

public class Main {

    public static void main(String[] args) throws IOException {
        BufferedReader reader = new BufferedReader(new InputStreamReader(in));
        String[] inputs = reader.readLine().split(" ");
        int X = Integer.parseInt(inputs[0]);
        int Y = Integer.parseInt(inputs[1]);
        double X1 = X * 1000 / 360.0;
        double Y1 = Y * 1000 / 360.0;


        int N = Integer.parseInt(reader.readLine());
        inputs = reader.readLine().split(" ");
        boolean result = true;
        for (int i = 0; i < N - 1; i++) {
            int first = Integer.parseInt(inputs[i]);
            int second = Integer.parseInt(inputs[i + 1]);

            double tmp = (double) first / X1;
            if (tmp * Y1 > second) {
                result = false;
                break;
            }
        }
        if(result) {
            System.out.println("YES");
        } else {
            System.out.println("NO");
        }
    }

}