#include<fstream.h>

ifstream fin("cifre1.in");
ofstream fout("cifre1.out");

int main()
{long long n,nr=0,x,c;
fin>>n;
if(n>=10)
  {for(x=10,c=2;x<=1000000000;x=x*10,c++)
     if(n/x<=10)  if(n!=x*10) break;
                      else {nr=1;
                            break;
                           }
  while(x>=10)
     {nr=nr+(n-x+1)*c;
      n=x-1;
      x/=10;
      c--;
    }
  nr=nr+9;
  }
  else nr=n;
fout<<nr;
fin.close();
fout.close();
return 0;
}