#include <iostream>
#include <conio.h>
using namespace std;
int main()
{
	double calc=0;
	int n;
	cout << "Enter the number of sequence members: n=";
	cin >> n;
	for ( int i = n; i>0; i--)
	{
		calc = sqrt(calc + i);

	}
	cout << calc;
	_getch();
	return 0;
}