Subsets (1) X86812

Write a program that, given n different words s₁, …, s_n, prints all the subsets that can be made up with the words.

Input

Input consists of a number n > 0, followed by s₁, …, s_n.

Output

Print all the subsets that can be made up with s₁, …, s_n.

Information about the checker

You can print in any order both the solutions and the elements inside each solution.