The milk specialty store packs the milk into two packs of one bag and three packs of one bag. Master Wang wants to buy 25 packs of milk, how many different ways are there?
牛奶专卖店把牛奶包装成2包一袋和3包一袋两种规格．王师傅要买25包牛奶，有多少种不同的买法？
<result>4</result>