string = readlines

string.each_with_index do |line, index|
  if index + 1 == string.length
    print "NO"
    return
  end
  length = line.length
  length.times do |i|
    current_char = string[length]
    if current_char == "L" && length - i == 5
      length = length + 1
      next_char = string[length]
      if next_char == "O" && length - i == 4
        length = length + 1
        next_char = string[length]
        if next_char == "V" && length - i == 3
          length = length + 1
          next_char = string[length]
          if next_char == "E" && length - i == 2
            print "YES"
            return
          end
        end
      end
    end
  end

end