有三对母子狮子Aa、Bb与Cc，其中ABC为母狮，abc为小狮。要过一条河，河边只有一条船，狮子自己划船，船每次只能载两只狮子。

生存准则：一只小狮如果没有母亲的保护，则会被其它母狮吃掉。母狮之间、小狮之间是安全的。

问题：如何安全过河？

-Lions have three pairs of mother and Aa, Bb and Cc, which ABC is a lioness, abc is a small lion. To cross a river, the river is only one ship, the lion his boat, the ship can only contain two lions. Living standards: a small lion without the protection of the mother, will be eaten by the other lioness. Lioness between, between the small lion is safe. Question: how to safely cross the river?