A, 2, ... K in 52 playing cards (remove king and king) correspond to natural numbers 1, 2, ..., 13 respectively. Randomly draw 3 sheets, if the single digit of the sum of numbers is 9 (that is, the sum is 9, 19, 29 or 39), remove it, and put the single digit of the sum of numbers not 9 into it. Repeating this way, how many possibilities are there for the number corresponding to the last remaining card.
将52张扑克牌(去掉大王，小王)中的A，2，…K，分别对应自然数1，2，…，13．从中任意抽取3张，若数字和的个位数字为9(即和为9，19，29或39)，则将其去掉，数字和的个位数不为9的仍放入其中．这样重复下去，最后余下的一张对应的数字有多少种可能．
<result>2</result>