input: Write a python function to check if the input arguments are integers.
  assert check_input(10, 20) == "The input is valid!"
  assert check_input("10", 20) == "The input must be a number!"
  assert check_input(10, "twenty") == "The input must be a number!"
  assert check_input(10, 20.5) == "The input must be a number!"
output: def check_input(*args):
      for arg in args:
          if not isinstance(arg, int):
              return "The input must be a number!"
      return "The input is valid!"