# import sys; input = sys.stdin.buffer.readline
# sys.setrecursionlimit(10**7)
from collections import defaultdict
con = 10 ** 9 + 7; INF = float("inf")

def getlist():
	return list(map(int, input().split()))


#処理内容
def main():
	N, M = getlist()
	for i in range(N):
		s = input()
		if "LOVE" in s:
			print("YES")
			return

	print("NO")

if __name__ == '__main__':
	main()