Problem:
Score : 200 points

Problem Statement

Given is a sequence of N integers A_1, \ldots, A_N.

Find the (multiplicative) inverse of the sum of the inverses of these numbers, \frac{1}{\frac{1}{A_1} + \ldots + \frac{1}{A_N}}.

Constraints

1 \leq N \leq 100

1 \leq A_i \leq 1000

Input

Input is given from Standard Input in the following format:

N
A_1 A_2 \ldots A_N

Output

Print a decimal number (or an integer) representing the value of \frac{1}{\frac{1}{A_1} + \ldots + \frac{1}{A_N}}.

Your output will be judged correct when its absolute or relative error from the judge's output is at most 10^{-5}.

Sample Input 1

2
10 30

Sample Output 1

7.5

\frac{1}{\frac{1}{10} + \frac{1}{30}} = \frac{1}{\frac{4}{30}} = \frac{30}{4} = 7.5.

Printing 7.50001, 7.49999, and so on will also be accepted.

Sample Input 2

3
200 200 200

Sample Output 2

66.66666666666667

\frac{1}{\frac{1}{200} + \frac{1}{200} + \frac{1}{200}} = \frac{1}{\frac{3}{200}} = \frac{200}{3} = 66.6666....

Printing 6.66666e+1 and so on will also be accepted.

Sample Input 3

1
1000

Sample Output 3

1000

\frac{1}{\frac{1}{1000}} = 1000.

Printing +1000.0 and so on will also be accepted.

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Wrong Answer)

import java.util.Scanner;


public class Main {

	public static void main(String[] args) {

    	Scanner parameter = new Scanner(System.in);

    	String[] line1 = parameter.nextLine().split(" ");
        String[] line2 = parameter.nextLine().split(" ");

        int[] intNumber = new int[line2.length];
        int maxNumber = 0;

        for (int i = 0; i < line2.length; i++) {

        	intNumber[i] = Integer.parseInt(line2[i]);

        	if (maxNumber < intNumber[i]) {

        		maxNumber = intNumber[i];
        	}
        }

        double sumNumber = 0;

        for (int nowNumber : intNumber) {

        	sumNumber = sumNumber + maxNumber/ nowNumber;
        }

        double lastNumber = maxNumber / sumNumber;

        System.out.println(lastNumber);
    }
}