n = int(input())
def f(num):
num += 1
while num % 10 == 0:
num //= 10
return num
dostizh_nums = set()
while n not in dostizh_nums:
dostizh_nums.add(n)
n = f(n)
print(len(dostizh_nums))#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define el '\n'
#define ll long long
#ifndef ONLINE_JUDGE
#include "Debug.cpp"
#else
#define debug(...) 42
#endif
void solve ( ) {
int n;cin>>n;
ll cnt = 9 ;
while(n>=10)
{
cnt+=10-n%10 ;
n+=10-n%10 ;
while(n%10==0) {
n/=10 ;
}
}
cout<<cnt<<el ;
}
int main ( ) {
ios_base::sync_with_stdio ( 0 );
cin.tie ( 0 );
cout.tie ( 0 );
int t = 1;
// cin >> t;
for ( int i = 0; i < t; i ++ ) {
solve ( );
}
}
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470. Implement Rand10() Using Rand7() | 866. Prime Palindrome |
1516A - Tit for Tat | 622. Design Circular Queue |
814. Binary Tree Pruning | 791. Custom Sort String |
787. Cheapest Flights Within K Stops | 779. K-th Symbol in Grammar |
701. Insert into a Binary Search Tree | 429. N-ary Tree Level Order Traversal |
739. Daily Temperatures | 647. Palindromic Substrings |
583. Delete Operation for Two Strings | 518. Coin Change 2 |
516. Longest Palindromic Subsequence | 468. Validate IP Address |
450. Delete Node in a BST | 445. Add Two Numbers II |
442. Find All Duplicates in an Array | 437. Path Sum III |
436. Find Right Interval | 435. Non-overlapping Intervals |
406. Queue Reconstruction by Height | 380. Insert Delete GetRandom O(1) |