import java.io.FileNotFoundException;
import java.util.Arrays;
import java.util.Comparator;
import java.util.Scanner;

public class Main {
	public static void main(String[] args) throws FileNotFoundException {
		new Main().run();
	}

	void run() throws FileNotFoundException {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int m = sc.nextInt();
		String[] map = new String[n];
		for (int i = 0; i < n; ++i) {
			map[i] = sc.next();
		}
		for (int i = 0; i < n; ++i) {
			for (int j = 0; j + 4 <= map[i].length(); ++j) {
				if (map[i].substring(j, j + 4).equals("LOVE")) {
					System.out.println("YES");
					return;
				}
			}
		}
		System.out.println("NO");
	}

	void tr(Object... objects) {
		System.out.println(Arrays.deepToString(objects));
	}
}