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.

#import sys
# import math
# import bisect
# import collections
# import itertools
# #from sys import stdin,stdout
# from math import gcd,floor,sqrt,log
# from collections import defaultdict as dd, Counter as ctr
# from bisect import bisect_left as bl, bisect_right as br
# from itertools import permutations as pr, combinations as cb

#sys.setrecursionlimit(100000000)

#$#$#$#$#$#$#$#$#$#$#$#$#$#$#$#$#$#$#$#$#$#$#$#$#$#$#$#$#$#$#$

inp    = lambda: int(input())
# strng  = lambda: input().strip()
# jn     = lambda  x,l: x.join(map(str,l))
strl   = lambda: list(input().strip())
# mul    = lambda: map(int,input().strip().split())
# mulf   = lambda: map(float,input().strip().split())
seq    = lambda: list(map(int,input().strip().split()))
#$#$#$#$#$#$#$#$#$#$#$#$#$#$#$#$#$#$#$#$#$#$#$#$#$#$#$#$#$#$#$
# p_inf = float('inf')
# n_inf = float('-inf')
#To find mex 
# def mex(arr):
#     nList = set(arr)
#     mex = 0
#     while mex in nList:
#         mex += 1
#     return(mex)

def results(n):
    a = set()
    def f(t):
        t += 1
        while t % 10 == 0:
            t = t // 10
        return(t)
    while not (n in a):
        a.add(n)
        n = f(n)
    return(len(a))

def main():
    t = inp()
    print(results(t))

if __name__ == '__main__':
    main()