#!/bin/python3

import sys

def sumOfGroup(k):
    # Return the sum of the elements of the k'th group.
    temp=k
    rang=1
    while(k!=0):
        rang=rang*k
        k=k-1
    list_odd=[]
    for j in range(1,rang*2):
        if j%2!=0:
           list_odd.append(j)  
    #print(list_odd)
    
    final_list=[]
    num_list=[]
    summ=0
    for i in range(0,temp+1):
        num_list=[]
        for z in range(0,i):
            num_list.append(list_odd.pop(0))
        #print(num_list)
        if i==temp:
            for i in num_list:
                summ=summ+i
    
    return summ
        

if __name__ == "__main__":
    k = int(input().strip())
    answer = sumOfGroup(k)
    print(answer)