Xiaomeng has 10 cards of flying spirits, 15 grass spirits and 20 fire spirits. She puts 45 cards in a bag and touches them with her eyes closed. Then he must touch at least how many cards to ensure that he can touch them. There are both flying elves and fire elves in the cards.
小孟有10张飞行系精灵、15张草系精灵和20张火系精灵的卡片，她把45张卡片放在袋子里闭着眼睛向外摸卡片，那么他至少摸多少张，才能保证摸出的卡片中同时有飞行系精灵和火系精灵的卡片．
<gadget id="calculator">15 + 20 + 1</gadget>
<output>36</output>

<result>36</result>