#include<bits/stdc++.h>
using namespace std;
int a,s;
int f(int n)
{
	int r;
	if(n==1) r=a;
	else
	{
		r=f(n-1)*10+a;
	}
	return r;
}
int main(){
	cin>>a;
	for(int i=1;i<=a;i++)
	{
		s=a+f(i);
	}
	cout<<s;
    return 0;
}
/**************************************************************
	Problem: 1245
	User: chenzhuo1
	Language: C++
	Result: Wrong Answer
****************************************************************/