def gcd(x,y):
	return x if y == 0 else gcd(y,x%y)
N = input()
n = int(N)
s = set(map(int,list(N)))
if len(s) == 1:
	print(N)
else:
	G = n
	for i in s:
		for j in s:
			if i < j:
				if G == 0:
					G = 9 * (j - i)
				else:
					G = gcd(G,9 * (j - i))
	print(G)