command /book:
    trigger:
        if player has 1 book named "A":
        if player has 1 book named "B":
            remove 1 book named "A" from player's inventory
            remove 1 book named "B" from player's inventory
            add 5 to {money::%player%}
            send "&7[&6Q-RPG&7]&a売りました。"
        else:
            send "&7[&6Q-RPG&7]&cアイテムが足りません。"