if __name__== "__main__":

	s = input('string : ')
	n = len(s)
	print(-n, ' <= k <= 0')
	k = int(input('k : '))
	
	k in range(-n, 1)
	j = k + n
	if s[k] == s[j]:
		print('j :', j)
		print('s[k] : ', s[k], 's[j] : ', s[j])
