Competitions

Arithmetical mean

The sequence of integers is given. Find its arithmetical mean.

Input

In one line the integers are given, each of the numbers is no more than 100 by absolute value.

Output

Print the arithmetical mean of all elements in the sequence. Print the answer with 4 decimal digits.

Time limit 1 second
Memory limit 128 MiB
Input example #1
1 2 3 4 5

Output example #1
3.0000

Input example #2
5 5 7 1 2 9

Output example #2
4.8333