from itertools import product
from fractions import gcd

g = input()

digits = sorted(map(eval, str(g)))

if len(set(digits)) == 1:
  print g
else:
  digit_len = len(str(g))
  digits = list(set(digits))
  G = g
  for x in product(digits, repeat=2):
    G = gcd(G, 9 * (x[0] - x[1]))
  print G