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

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