a = list(map(int, input()))
k = 1
for i in range(len(a) - 1):
    for j in range(len(a) - i - 1):
        if a[j] > a[j + 1]:
            a[j], a[j + 1] = a[j + 1], a[j]
while a[k] == a[k - 1]:
    k += 1
print(k)