from fractions import gcd
import random
s = list(input())
if set(s) == 1:
	print(s)
else:
	ans = -1
	for _ in range(100):
		random.shuffle(s)
		num = int("".join(s))
		if ans == -1:
			ans = num
		ans = gcd(ans,num)

	print(ans)