import math

s = raw_input()
st = set()
for i in s:
    st.add(int(i))

ans = int(s)

if len(st) == 1:
    print(ans)
else:
    for i in st:
        for j in st:
            if j > i:
                ans = math.gcd(ans, 9*(j - i))
    print(ans)