class Problem0700:
    def solve(this):
        n,m = map(int, input().split())

        res = False
        for i in range(n):
            s = input().find("LOVE")
            if res == False and s != -1:
                res = True
        if res:
            print("YES")
        else:
            print("NO")
if __name__ == "__main__":
    problem = Problem0700()
    problem.solve()