SELECT DISTINCT T4.name FROM PersonFriend AS T1 JOIN Person AS T2 ON T1.name  =  T2.name JOIN PersonFriend AS T3 ON T1.friend  =  T3.name JOIN PersonFriend AS T4 ON T3.friend  =  T4.name WHERE T2.name  =  'Alice' AND T4.name != 'Alice'
Find Alice's friends of friends.
[Schema (values) (types)]: | network_2 |  Person : name (text) , age (text) , city (number) , gender (text) , job (text) | PersonFriend : name (text) , friend (text) , year (number);