There are 54 cards in a deck plus big and small kings. At least how many cards are drawn will ensure that there are two cards of the same color.
一副扑克牌加上大、小王共有54张，至少抽取多少张牌就一定能保证有两张同色．
<gadget id="calculator">4 + 2 + 1</gadget>
<output>7</output>

<result>7</result>