C :

#include <stdio.h>

int main(void) {
	int i, n;
	double s = 0;
	scanf("%d", &n);
	for(i = 1; i <= n; i ++)
		s = s + (double)1 / i;
	printf("%.4lf", s);
	return 0;
}

C++ :

#include<cstdio>
using namespace std;
int main()
{
	int i,n;
	double s=0;
	scanf("%d",&n);
	for(i=1;i<=n;i++)
	{
		s=s+1.0/i;
	}
	printf("%.4lf\n",s);
	return 0;
}

Pascal :

var i,n:longint;
     s:real;
begin
  readln(n);
  s:=0;
  for i:=1 to n do
    s:=s+1/i;
  writeln(s:0:4);
end.