Average at Even Indices

Given a list of integers, you are to calculate the average of the elements located at even indices (0-indexed). That is, consider the elements at positions 0, 2, 4, etc. If the list is empty, the average is defined as \(0.0\). Use standard input/output methods for reading input and producing output.

inputFormat

The first line contains an integer \(n\), the number of elements in the list. The second line contains \(n\) space-separated integers. If \(n=0\), no further numbers are provided.

outputFormat

Output a single floating point number representing the average of the numbers at even indices. If no such elements exist, output \(0.0\).

5
1 2 3 4 5

3.0