Problem description.

Shyam has his computer science  exam next week . He is solving one problem but he is  not able to  write the  program
that for that . As a good programmer you thought that you will help so help him  by writing a program that solves that problem .
The problem is that you have N boxes numbered from 1 to N and you have cards that are numbered from 1 to N . There are N cards of
each type . You have to place one card in each box such that the cards form a non decreasing sequence . Find the number of
ways you can place them in the boxes . Since it is a non decreasing sequence you can place a card of one type multiple times
but remember it has to be a non decreasing sequence .

INPUT :-

It consists of one line and that contains N

OUTPUT :-

output the number of ways

Constraints :-

0 < N < 15

Ex :

Input :

2

Ouput :

3

Explanation:
Sequence are 1)    1 , 1      2)  1 , 2       3)  2 , 2
from math import *
n = int(raw_input())
print factorial(2*n-1)/(factorial(n)*factorial(n-1))