from itertools import permutations
from fractions import gcd

n = input()

g = -1
checked = set()

for np in permutations(n, len(n)):
    x = int(''.join(np))
    if g == -1:
        g = x
    elif g == 1:
        break
    elif x in checked:
        continue
    else:
        checked.add(x)
        g = gcd(x, g)

print(g)