A deck of poker cards has 4 suits (except big and small kings), and each suit has 13 cards, from which cards are randomly drawn, at least how many cards must be drawn to ensure that 4 cards are of the same suit.
一副扑克牌有4种花色(大小王除外)，每种花色有13张，从中任意抽牌，最少要抽多少张牌，才能保证有4张牌是同一花色的．
<gadget id="calculator">3 * 4</gadget>
<output>12</output>

<gadget id="calculator">12 + 1</gadget>
<output>13</output>

<result>13</result>