Painful looking code

Code that makes you experience physical pain, nausea, and/or symptoms of high blood pressure.  Merely cringing is not enough.

I barely avoided vomiting while looking at this one http://codereview.stackexchange.com/questions/14528/python-script-very-slow-any-help-to-optimise

Just in case the author (who must be Satan) deletes his masterpiece, I made an unauthorized copy http://pastebin.com/zkuHK16n

>>18
Not so much Church numerals as Peano numbers. Church numerals are the same thnig constructed out of only lambdas. On the topic of which, a favourite of mine is
(display
  ((lambda (d)
     ((lambda (n)
        ((lambda (s)
           ((lambda (f) (((f f) n) 0))
            (lambda (f)
              (lambda (n)
                (lambda (w) (if (= n 0) ""
                              ((lambda (c) (string-append (((f f) (d n)) (max w (string-length c))) (if (= w 0) "" (make-string (floor (/ (- w (string-length c)) 2)) #\ )) c)) (s n))))))))
         (lambda (n)
           ((lambda (b)
              ((lambda (f) (((f f) (d n)) 0))
               (lambda (f)
                 (lambda (n)
                   (lambda (k) (string-append (number->string ((b n) k)) (if (= n k) "\n" (string-append " " (((f f) n) (1+ k))))))))))
            (lambda (n)
              (lambda (k)
                ((lambda (f) (((f f) n) k))
                 (lambda (f)
                   (lambda (n)
                     (lambda (k) (if (= k 0) 1 (/ (* n (((f f) (d n)) (d k))) k)))))))))))) 30))
   (lambda (n) (- n 1))))