#include<bits/stdc++.h>
using namespace std;
int n;
int f(int a){
	int r;
	if(a==1) r=n;
	else  {
		r=f(a-1)*10+n;
	}
	return r;
}

int main(){

	int s=0;
	cin>>n;
	for(int i=1;i<=n;i++){
	//cout<<i<<" "<<f(i)<<endl;
	s=s+f(i);
	} 
   cout<<s;
  
	return 0;
}



/**************************************************************
	Problem: 1245
	User: hulaoshi
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/