text: def coding_problem_05():
      """
      cons(a, b) constructs a pair, and car(pair) and cdr(pair) returns the first and last element of that pair.
      Given this implementation of cons below, implement car and cdr.
  
      >>> def cons(a, b):
      ...     def pair(f):
      ...         return f(a, b)
      ...     return pair
  
      >>> car, cdr = coding_problem_05()
      >>> car(cons('first', 'last')) == 'first'
      True
  
      >>> cdr(cons('first', 'last')) == 'last'
      True
      """
      pass
  