import random
import fractions
s = input()
n = int(s)
a = [0]*10
for i in s:
	a[int(i)]+=1

ans = n

for i in range(10):
	for j in range(i):
		if a[i] and a[j]:
			if ans < 0:
				ans = 9*(i-j)
			else:
				ans = fractions.gcd(ans, 9*(i-j))

print(ans)