import math,itertools
def g(e):
    n=list(itertools.permutations(e))
    for i in range(len(n)):
        n[i]=int("".join(n[i]))
    x=n[0]
    for i in range(1,len(n)):
        x=math.gcd(n[i],x)
    return x
print(g(input()))