#include <stdio.h>
#include <string.h>

int main(void) {
	char S[51];
	int i, j, n, m, c = 0, c1 = 0;

	scanf("%d%d", &n, &m);
	for (i = 0; i < n; i++) {
		scanf("%s", S);
		for (j = 0; j < m; j++) {
			if (strncmp(&S[j], "LOVE", 4) == 0) {
				c++;
			}
		}
	}
	if (c > 0) {
		printf("YES\n");
	}
	else {
		printf("NO\n");
	}
}