#include<bits/stdc++.h>
using namespace std;
int t(int a){
int n;
    int r;
    if(a==1) r=n;
    else  {
        r=t(a-1)*10+n;
    }
    return r;
}
int main(){
    int s=0;
    cin>>n;
    for(int i=1;i<=n;i++){   
    s=s+t(i);
    } 
   cout<<s;
    return 0;
}
/**************************************************************
	Problem: 1245
	User: lijinkai
	Language: C++
	Result: Compile Error
****************************************************************/