import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int m = sc.nextInt();

        for (int i = 0; i < n; i++) {
            String s = sc.next();
            if (s.indexOf("LOVE") > -1) {
                System.out.println("YES");
                return;
            }
        }

        System.out.println("NO");
    }
}