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

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