func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     int n;     cin >> n;     set<int> s;     while (1) {       int k = s.size();       s.insert(n);       int m = s.size();       if (k == m) break;       n = n + 1;       while (n % 10 == 0) {         n = n / 10;       }     }     cout << s.size() << endl;     return 0;   }   