class Queue
  def initialize(max_size)
    @store = []
    @max_size = max_size
    @length = 0
  end

  def push(x)
    if @length < @max_size
      @length += 1
      @store.push x
    else
      raise "Queue Overflow - The queue is full"
    end
  end

  def shift
    raise "Queue Underflow - The queue is empty" if self.empty?
    @length -= 1
    @store.shift
  end

  def peek
    @store.first
  end

  def empty?
    @store.empty?
  end

  def full?
     puts "The queue is full" if @length >= @max_size
  end
end