#include <bits/stdc++.h>
using namespace std;

typedef long long int lli;

int main(){
   lli in,ans = 0;
   cin >> in;

   if(in < 10)
      cout << in << endl;
   else{
      lli digits = 0;
      lli temp = in;
      while(temp > 0){
         digits++;
         temp /= 10;
      }
      digits--;
      
      while(in > 0){
         //cout << "in: " << in << endl;
         //cout << "digits: " << digits << endl;
       
         ans += ((in - (pow(10,digits) - 1)) * (digits + 1));
         in = in -  (in - (pow(10,digits) - 1));
         digits--;
         
         if(in == 9){
            ans+= 9;
            break;
         }
      }
      cout << ans << endl;
   }
}