Ruby syntax error, unexpected end-of-input, expecting keyword_end

I'm trying to create the basics of a card game. While creating/testing my initial deck I keep getting the following error message when I run my ruby code.

gofish.rb:30: syntax error, unexpected '\n', expecting :: or '[' or '.'
gofish.rb:73: syntax error, unexpected end-of-input, expecting keyword_end
deck.add_cards

I looked up possible solutions and I can't seem to find my missing end. Could it possibly be something else? I'm very new to ruby.

class Deck

    def initialize
        @ranks = %w(2 3 4 5 6 7 8 9 10 Jack Queen King Ace)
        @suits = %w(Clubs Spades Hearts Diamonds)
        @cards = []

        @ranks.each do |rank|
            @suits.each do |suit|
                @cards << Card.new(rank, suit)
            end
        end
    end

    def shuffle
        @cards.shuffle
    end

    def deal
        @cards.shift
    end

    def empty?
        @cards.empty?
    end

    def add_cards(*cards)
        *cards.each do |card|
            @cards << card
        end #line 30
    end

    def to_s
        output = ""

        @cards.each do |card|
            output = output + card.to_s + "\n"
        end

        return output
    end
end

class Hand

    def initialize
    end

    def search()
    end
end

class Card

    attr_reader :rank, :suit

    def initialize(rank, suit)
        @rank = rank
        @suit = suit
    end

    def to_s
        "#{@rank} of #{@suit}"
    end
end

deck = Deck.new

puts deck.to_s
deck.shuffle
puts deck.to_s
deck.deal
deck.add_cards #line 73