/* package whatever; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		Scanner in = new Scanner(System.in);
		
		int n = in.nextInt();
		
		double a, p=1, k;
		
		for(int i=1; i<=n; i++){
			a = in.nextDouble();
			p*=a;
		}
		k=Math.sqrt(Math.abs(p));
		System.out.println(k);
	}
}