#include<iostream>
using namespace std;
int main()
{
	int n,p,c,s,z;
	cin>>n;
	p=9;
	c=1;
	z=1;
	s=0;
	while(p<n)
	{
		s=s+9*c*z;
		p=p*10+9;
		c++;
		z=z*10;
	}
	s=s+(n-p/10)*c;
	cout<<s;
}