(define side-a-titles
  (lambda (titles length)
    (if (null? titles)
        '()
        (if (> (cdr (car titles))
               length)
            (side-a-titles (cdr titles) length)
            (let ((solution-1
                   (cons (car titles)
                         (side-a-titles (cdr titles)
                                        (- length (cdr (car titles))))))
                  (solution-2
                   (side-a-titles (cdr titles) length)))
              (if (> (titles-length solution-1)
                     (titles-length solution-2))
                  solution-1
                  solution-2))))))

(define titles-length
  (lambda (titles)
    (if (null? titles)
	0
	(+ (cdr (car titles))
	   (titles-length (cdr titles))))))