There are 4 students exchanging souvenirs in the graduation party. Any two students can exchange at most once, and the two students who are exchanging will give each other a souvenir. It is known that the 4 students have exchanged 5 times. Then how many students received 2 souvenirs?
有4位同学在毕业聚会活动中进行纪念品的交换，任意两位同学之间最多交换一次，进行交换的两位同学互赠一份纪念品，已知4位同学之间共进行了5次交换，则收到2份纪念品的同学人数为多少人．
<result>2</result>