Standard input will contain a single positive integer N < 20. Write a program that writes out all finite non-empty increasing sequences that can be formed from the set {1, 2, ..., N}. We consider even a single-element sequence to be increasing. Write each increasing sequence to its own line, separating terms of the sequence wih a single space.
You may write the increasing sequences in any order.

Sample input:

3 

Corresponding output (in any order of lines):

1 1 2 1 2 3 1 3 2 2 3 3