Pusheen recently got her report card back! Pusheen took $N$ classes last semester and wants to know her average mark. She was rather burnt out from all the critical thinking and real-time programming that she had to do, so she needs your help to figure out her average mark.

Pusheen defines her average mark to be the arithmetic mean of the marks that she received - namely, the sum of her marks divided by the number of courses she took.

Constraints

$N\in \{1,2,5,10\}$

$0\le a_i\le 100$

In tests worth 3 marks, $N=1$.

In additional tests worth 5 marks, $N=10$.

Input Specification

The first line contains a single positive integer, $N$.

$N$ lines follow, each containing a single nonnegative integer $a_i$, indicating Pusheen's mark in class $i$.

Output Specification

Output, with exactly one digit after the decimal point, Pusheen's average mark.

Make sure your lines end properly with a newline character. This holds true for all problems.

Sample Input

2
100
0

Sample Output

50.0