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


/**************************************************************
	Problem: 1245
	User: 15159808820
	Language: C++
	Result: Accepted
	Time:7 ms
	Memory:2072 kb
****************************************************************/