input: Write a python function to determine if a given character is an uppercase or lowercase alpha character.
  assert check_alpha_case('A') == "uppercase"
  assert check_alpha_case('a') == "lowercase"
  assert check_alpha_case('1') == False
  assert check_alpha_case('Z') == "uppercase"
  assert check_alpha_case('z') == "lowercase"
output: def check_alpha_case(char):
      if 'A' <= char <= 'Z':
          return "uppercase"
      elif 'a' <= char <= 'z':
          return "lowercase"
      else:
          return False