#include<bits/stdc++.h>
using namespace std;
int a,s=0;
int f(int n){
    int r=0;
    if(n==1) r=a;
    else r=f(n-1)*10+a;
    return r;
}
int main(){
    cin>>a;
    for(int i=1;i<=a;i++){
        s=s+f(i);
    }
    cout<<s;
 
    return 0;
}
/**************************************************************
	Problem: 1245
	User: chenzhuo1
	Language: C++
	Result: Accepted
	Time:7 ms
	Memory:2072 kb
****************************************************************/