class INT{} class list<A>{ A a = null; list<A>next = new list(); void insert(A elem){ if(a = null){ a=elem; } else{ next.insert(elem); } } void get(A elem){ System.out.println(elem); next.get(elem); } } class main extends list<list<INT>> { list <INT>l = new list(); void main(){ list<INT>s= new list(), <INT>l = new list(); INT i = new INT(); } }