Harmonic mean is one of the ways to calculate the average of a series. It is the reciprocal of the arithmetic mean of reciprocals.

Question: Write a program that calculates the harmonic mean of n numbers.

Input specification
You will be first given a number n, the number of numbers where 0 ≤ n ≤ 1,000. Then, in the following line, you will be given n numbers where the numbers are floating point numbers greater than 0 and less than 50,000.

Output specification:
Show one floating point number with 2 digits precision.

Explanation: There are 3 numbers given. And, sum of reciprocals (1/5) + (1/6) + (1/1) = 1.3667 Then, the Harmonic mean is 3/1.3667 = 2.1951