#include<bits/stdc++.h>
using namespace std;
int n,h=0;
   int f(int x){
   	   if(x==1) return n;
   	   else return f(x-1)*10+n;
   }
int main(){
	cin>>n;
	for(int i=1;i<=n;i++){
		h=h+f(i);
	}
	cout<<h;

	return 0; 
}

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