#include <iostream>
using
namespace
std;
int
fum(
int
n)
{
int
t,sum,a;sum=t=0;a=2;
while
(n>0)
{ t=t+a;
a=a*10;
sum=sum+t;
n--;
}
return
sum;
}
int
main()
{
int
n,sn;
cin>>n;
sn=fum(n);
cout<<sn<<endl;
return
0;
}