# Write a python function to find the average of even numbers till a given even number.
def average_Even(n):
    if n % 2 != 0:
        return "Invalid Input"
        return -1
    sm = 0
    count = 0
    while n >= 2:
        count = count + 1
        sm = sm + n
        n = n - 2
    return sm // count
