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

	return 0;
}

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