'''
You are provided with a number "N", Find the Nth term of the series: 1, 4, 9, 25, 36, 49, 64, 81, .......

(Print "Error" if N = negative value and 0 if N = 0).

Input Description:
An integer N is provided to you as the input.

Output Description:
Find the Nth term in the provided series.

Sample Input :
18
Sample Output :
324'''
number = int(input())
a = []
for i in range(0,number+1):
  a.append(i*i)
print(round(a[-1]))
