#lang racket
 
(define (programming048 . args)
  (foldl (lambda (s-2 s-1)
           (string-append s-1
                          (substring s-2
                                     (foldl (lambda (cnt init)
                                              (if (string-ci=? (substring s-1 (- (string-length s-1) cnt))
                                                               (substring s-2 0 cnt))
                                                  cnt
                                                  init))
                                            0
                                            (range 1 (add1 (apply min (map string-length `(,s-1 ,s-2)))))))))
         (car args) (cdr args)))

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