class PhraseFinder
  def initialize(phrase = 'LOVE')
    @n, _ = gets.split(' ').map(&:to_i)
    @phrase = phrase
    @found = false
  end

  def find!
    @n.times do
      @found = true and break if found?
    end
    puts @found ? 'YES' : 'NO'
  end

  private

  def found?
    gets.include?(@phrase)
  end
end

PhraseFinder.new.find!