060.scm

(add-load-path "." :relative)
(use eulerlib)

(define (e60)
  (define (satisfy? l p)
    (let1 pl (integer->list p)
      (if (every prime?
                 (append-map
                   (^i (let1 m (integer->list i)
                         `(,(list->integer (append pl m))
                             ,(list->integer (append m pl)))))
                   l))
          (cons p l)
          #f)))
  (let1 ps (delete 5 (delete 2 (primes 10000)))
    (call/cc
      (^(return)
         (dolist (p ps)
           (let loop ((l `(,p)) (ps (cdr (member p ps))))
             (cond ((null? ps) #f)
                   ((satisfy? l (car ps))
                    => (^m (if (= (length m) 5)
                               (return (apply + m))
                               (unless (loop m (cdr ps))
                                       (loop l (cdr ps))))))
                   (else (loop l (cdr ps))))))))))