func_code_string: #include <bits/stdc++.h>   using namespace std;   const int MAXN = 1e5 + 100;   const long long INF = 1e12;   int solve(long long x) {     int res = 0;     while (x) {       res += (x % 10);       x /= 10;     }     return res;   }   int main() {     ios::sync_with_stdio(false);     long long n;     while (cin >> n) {       long long tmp = 0, b = 0;       while (1) {         tmp = tmp * 10 + 9;         if (tmp > n) break;         b = tmp;       }       cout << solve(b) + solve(n - b) << endl;     }     return 0;   }   