## Problem Description

There are 13 possible orderings for three numbers, if we sort them with the relation '<' and '=':

A = B = C , A = B < C , A < B = C ,A < B < C

A < C < B , A = C < B , B < A = C ,B < A < C

B < C < A , B = C < A , C < A = B ,C < A < B

C < B < A

Given an integer n, your task is to find the number of possible orderings for any n real numbers.

## Input

There are several test cases. Each case contains only one integer n which is between 1 and 50.

## Output

Output the number of different orderings for any n real numbers.

## Sample Input

3

## Sample Output

13

## Source

FZU 2006 Summer Training II