(let ((ch (fileVal "chRSA")) (eea (fileVal "egcd")))
  (lambda (n str) (let* ((ps (ch n str)) (mod-exp (fileVal "mod-exp"))
    (inv (lambda (a p) (mod-exp a (- p 2) p)))
    (pq (car ps)) (p (cadr ps)) (q (caddr ps)) (e 17)
    (mg (let ((P (* p (inv p q)))(Q (* q (inv q p))))
        (lambda(a b) (modulo (+ (* b P)(* a Q)) pq))))
    (em (* (- p 1)(- q 1))))
  (if (> (gcd e em) 1) "Bad" (let* ((d (modulo (car (eea e em)) em))
        (pe (modulo d (- p 1)))(qe (modulo d (- q 1))))
    (cons (lambda (p) (mod-exp p e pq))
          (lambda (c) (mg (mod-exp (modulo c p) pe p)
                          (mod-exp (modulo c q) qe q)))))))))

(define t (fileVal "wRSA"))
(let ((pair (t 512 "frog"))) ((cdr pair) ((car pair) 374))) => 374
(let ((pair (t 2048 "grenouille"))) ((cdr pair) ((car pair) 374404))) => 374404