func_code_string: #include <bits/stdc++.h>   using namespace std;   using namespace std;   long long i, n, x, m, k, ans;   int main() {     cin >> n;     x = n;     while (x) {       x /= 10;       m++;     }     ans = n * m + m - 1;     k = 1;     for (i = 0; i < m - 1; i++) {       k *= 10;       ans -= k;     }     cout << ans << endl;     return 0;   }   