(define (same-parity fst . lst)
  (define (parity-list mod ls)
    (if (null? ls)
        null
        (if (= (remainder (car ls) 2) mod)
            (cons (car ls) (parity-list mod (cdr ls)))
            (parity-list mod (cdr ls)))))
  (cons fst (parity-list (remainder fst 2) lst)))