#include <bits/stdc++.h>   using namespace std;   void solve();   const int N = 10000005;   long long i, j, n, s;   int main() {     ios_base::sync_with_stdio(false);     cin.tie(NULL);     int t = 1;     while (t--) {       solve();       cout <<   n ;     }     return 0;   }   void solve() {     cin >> n;     for (i = 1; i <= n; i = i * 10) {       s += n - i + 1;     }     cout << s;   }   