C++ :

#include<iostream>
#include<cmath>
using namespace std;

int main()
{
	int n;
	double s=0.0;
	for (int i=1;i<=1000000;i++)
		s+=(1.0/i)*(1.0/i);
	s*=6;
	cout.precision(5);
	cout.setf(ios::fixed);
	cout<<sqrt(s)<<endl;
	return 0;
}

Pascal :

begin
  write('3.142');end.