Average of a Sequence

Source: Phước Hưng OJ

Version: Phuoc Hung OJ Extended

Problem Statement

Given integer n and exactly n real numbers, compute their arithmetic mean (sum divided by n). Print exactly two digits after the decimal point, including trailing zeroes.

Input

The first line contains n, followed by exactly n real numbers, possibly across several lines.

Output

Print the arithmetic mean using exactly two fractional digits (%.2f).

Subtasks

• Subtask 1 (20%): 1<=n<=5; all values are integers in [-10,10].
• Subtask 2 (30%): 1<=n<=200; all values are multiples of 0.5 in [-100,100].
• Subtask 3 (50%): 1<=n<=10000; all values are multiples of 0.5 in [-1000,1000].

Examples

Example 1

Input

3
1.5 2.5 3.5

Output

2.50

Explanation

The sum 7.5 divided by 3 is 2.5, formatted as 2.50.

Example 2

Input

1
-1.5

Output

-1.50

Explanation

The mean of one value is itself, formatted to two decimals.