input: Write a function to determine if an integer is even or odd.
  assert is_even_odd(4) == "The number is even"
  assert is_even_odd(7) == "The number is odd"
  assert is_even_odd(0) == "The number is even"
  assert is_even_odd(-3) == "The number is odd"
output: def is_even_odd(n):
      if n % 2 == 0:
          return "The number is even"
      else:
          return "The number is odd"