#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: chenlingxuan
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/