#include<iostream>
#include<stdlib.h>
#include<iostream>
#include<algorithm>
#include<math.h>
using namespace std;
int main()
{
long long int n,k,prev,ans,i;
cin>>n;
k=1;
prev=0,i=0;
ans=0;
while(i<n)
{
i=pow(10,k);
if(i<n)
{
ans+=((i-1)-prev)*k;
prev=i-1;
}
else if(i==n)
{
int x=((i-1)-prev)*k;
ans=ans+x;
ans=ans+k+1;
}
else
{
ans+=((n)-prev)*k;
}
k++;
}
cout<<ans;
}
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