func_code_string: #include <bits/stdc++.h>   using namespace std;   const double pi = 2 * acos(0);   unsigned long long int binpow(unsigned long long int b,                                 unsigned long long int n) {     if (n == 0) return 1;     if (n == 1) return b;     if (n & 1)       return binpow(b, n - 1) * b;     else       return binpow(b * b, n / 2);   }   long long int bigmod(long long int b, long long int n, long long int m) {     if (n == 0) return 1;     if (n % 2 == 0) {       long long int x = bigmod(b, n / 2, m) % m;       return (x * x) % m;     } else       return ((b % m) * bigmod(b, n - 1, m) % m) % m;   }   void start() {}   long long int to_num(string &s) {     stringstream second;     second << s;     long long int n;     second >> n;     return n;   }   long long int get(long long int n) {     long long int s = 0;     while (n) {       s += (n % 10);       n /= 10;     }     return s;   }   void solve() {     long long int n, cn = 0;     cin >> n;     string s = to_string(n), tmp =   ;     for (long long int i = 0; i < s.size() - 1; i++) {       tmp +=  9 ;     }     if (n < 10) {       cout << n <<   n ;       return;     }     cn = (s.size() - 1) * 9;     long long int left = n - to_num(tmp);     cn += get(left);     cout << cn <<   n ;   }   int main(int argc, char const *argv[]) {     ios_base::sync_with_stdio(false);     cin.tie(0);     cout.tie(0);     start();     solve();     return 0;   }   