#! /usr/bin/env python
"""
 catalan_recursion.py calculates the Catalan numbers via a recursive function.
    
 Catalan numbers C_0 = 1 & C_n = C_n-1 * (4n-2)/(n+1)

# for n=110 C_110 = 815663960219058384462569194343901173113117297781505394610791520



 Paul Eugenio 
 PHZ4151C
 Jan 25, 2019
"""

from __future__ import division, print_function



def catalan(n):
    """  
    Catalan recursive function defined via integer arithemtic 
    """
    if n==0:
    	return 1
    else:
        return (4*n-2)* catalan(n-1) // (n+1)

def catalan2(n):
    """ 
    Catalan recursive function defined with floating division which 
    is accurate to a precission of ~15 decimals
    """
    if n==0:
    	return 1
    else:
        return int((4*n-2)* catalan(n-1) / (n+1))

#
#
def catalan3(n):
    """
    Here is faulty Catalan recirsive function due to the order of the integer division
    """
    if n==0:
    	return 1
    else:
        return ((4*n-2)//(n+1)) * catalan(n-1)


  
#
# main
#

n = int(raw_input("Enter Catalan number index: "))

print("C_",n, "\n", catalan(n),"\n", catalan2(n),"\n", catalan3(n),"\n", sep='')