#include<bits/stdc++.h>
using namespace std;
int n,s=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++){
		s=s+f(i);
	} 
	cout<<s;
	return 0;
}


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