input: 
  def square_root(x):
      """Given a number 'x', returns the square root of 'x' if it's an integer.
      If 'x' is not an integer, raises a TypeError exception with the message 
      'Input must be an integer'.
      >>> square_root(4)
      2.0
      >>> square_root('4')
      Traceback (most recent call last):
          ...
      TypeError: Input must be an integer
      """
      if not isinstance(x, int):
          raise TypeError('Input must be an integer')
      return x**0.5
  
output:     if x < 0:
          raise ValueError('Input must be a non-negative integer')