#include <iostream>
#include <math.h>
using namespace std;
double wi(int i, double a)
{
	return i*sqrt(pow(i,2) - pow(a,2));	
}
int main() {
	int N= 10;
	double Wavgeom = 1;
	for (int i=1; i<=N; ++i)
		Wavgeom *= wi(i, 0.5);
	Wavgeom = pow(Wavgeom, pow(N, -1));
	std::cout  << Wavgeom;
}