Let's denote a function f(x) in such a way: we add 1 to x, then, while there is at least one trailing zero in the resulting number, we remove that zero. For example, 

  * f(599) = 6: 599 + 1 = 600 → 60 → 6; 
  * f(7) = 8: 7 + 1 = 8; 
  * f(9) = 1: 9 + 1 = 10 → 1; 
  * f(10099) = 101: 10099 + 1 = 10100 → 1010 → 101. 



We say that some number y is reachable from x if we can apply function f to x some (possibly zero) times so that we get y as a result. For example, 102 is reachable from 10098 because f(f(f(10098))) = f(f(10099)) = f(101) = 102; and any number is reachable from itself.

You are given a number n; your task is to count how many different numbers are reachable from n.

Input

The first line contains one integer n (1 ≤ n ≤ 10^9).

Output

Print one integer: the number of different numbers that are reachable from n.

Examples

Input


1098


Output


20


Input


10


Output


19

Note

The numbers that are reachable from 1098 are:

1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 13, 14, 15, 16, 17, 18, 19, 1098, 1099.
"""
contest template, Mikhail Dektyarev <mihail.dektyarow@gmail.com>
real code is below
"""
from sys import stderr


def readint():
    return int(input())


def readfloat():
    return float(input())


def readarray(n, f=input):
    return [f() for i in range(n)]


def readlinearray(f=int):
    return list(map(f, input().split()))


#gcd, x, y; a * x + b * y = gcd
def euclide(a, b):
    if a < 0:
        g, x, y = euclide(-a, b)
        return g, -x, y
    if b < 0:
        g, x, y = euclide(a, -b)
        return g, x, -y


def gen_primes(max):
    primes = [1] * (max + 1)
    for i in range(2, max + 1):
        if primes[i]:
            for j in range(i + i, max + 1, i):
                primes[j] = 0
    primes[0] = 0
    return [x for x in range(max + 1) if primes[x]]


def is_prime(N):
    if N % 2 == 0:
        return N == 2
    i = 3
    while i * i <= N:
        if N % i == 0:
            return False
        i += 2
    return True


def answer():
    return ""


def gcj():
    n = readint()
    was = set(range(1, 10))
    while n > 8:
        was.add(n)
        n += 1
        while n % 10 == 0:
            n //= 10
    print(len(was))


if __name__ == "__main__":
    gcj()
