#include <bits/stdc++.h>   using namespace std;   const int MOD = 1000000007;   const double EXP = 2.7182818284590452;   const double Pi = 3.14159265;   const double EPS = 1e-13;   const int INF = 1000 * 1000 * 1000;   const long long INFL = (long long)INF * (long long)INF;   long long n;   long long res;   void accept() {     cin >> n;     for (long long i = 1, j = 1; i <= INF; i *= 10, ++j) {       res += ((0 < (((n - i + 1) < 9L * i) ? ((n - i + 1)) : (9L * i)))                   ? ((((n - i + 1) < 9L * i) ? ((n - i + 1)) : (9L * i)))                   : (0)) *              j;     }     cout << res;   }   int main(void) {     accept();     return 0;   }   