<image> <image>

*The two images are equivalent, feel free to use either one.

Input

The input contains a single integer a (-100 ≤ a ≤ 100).

Output

Output the result – an integer number.

Example

Input


1


Output


1
from fractions import Fraction as F
import math
import sys
import random
import time

random.seed(time.time())

fi = sys.stdin
fo = sys.stdout
fe = sys.stderr
exit = sys.exit

readline = raw_input

def readargs(tp=None):
	if tp is not None:
		return map(tp, readline().split())
	return readline().split()

def yesno(flag, yes='', no=''):
	if flag:
		print yes if yes else 'YES'
	else:
		print no if no else 'NO'

truefalse = lambda flag : yesno(flag, yes='TRUE', no='FALSE')

n = int(readline())
print 2 - (n ** 2)
