#include <bits/stdc++.h>
using namespace std;
double t;
int i,n;
int main()
{
cin>>n;
t=0;
for (i=1; i<=n; i++)
t=t+(1*1.0)/(i*1.0);
cout<<fixed<<setprecision(2)<<t;
return 0;
}
Var i,n:integer;
s:real;
Begin
Write('Nhap n = ');readln(n);
For i:=1 to n do
s:=s+1/i;
Write('tong la ',s:10:2);
Readln;
End.