#include<iostream>
#include<cstdio>
#include<vector>
#include<cmath>
#include<climits>
using namespace std;
int main(){

	long long n;
	cin>>n;
	long long x=n;
	long long count=0;
	while(x>0){
	
		count++;
		x/=10;
	}
	long long ans=0;
	ans=(n-pow(10,count-1)+1)*count;
	for(long long i=count-2;i>=0;i--){
	
		ans+=9*pow(10,i)*(i+1);
	}
	cout<<ans<<endl;
}