import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		int n = scan.nextInt();
		int m = scan.nextInt();
		String []s = new String[n];
		for(int i = 0; i < n; i++) {
			s[i] = scan.next();
			if(s[i].length() != m) {
				break;
			}
		}
		scan.close();
		for(int i = 0; i < n; i++) {
			if(s[i].matches(".*LOVE.*")) {
				System.out.println("YES");
				System.exit(0);
			}
		}
		System.out.println("NO");
	}
}