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

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