input: Write a python function to count the number of even numbers in a list.
  assert countEvenNum([1, 2, 3, 4, 5]) == 2
  assert countEvenNum([10, 20, 45, 67, 84, 93]) == 3
  assert countEvenNum([5, 7, 9, 8, 6, 4, 3]) == 3
output: def countEvenNum(lst):
      return len([num for num in lst if num % 2 == 0])