IMPORTANT: Please do not post solutions, hints, or other spoilers until at least 60 hours after the date of this message. Thanks. IMPORTANTE: Por favor, no enviéis soluciones, pistas, o cualquier otra cosa que pueda echar a perder la resolución del problema hasta que hayan pasado por lo menos 60 horas desde el envío de este mensaje. Gracias. IMPORTANT: S'il vous plaît, attendez au minimum 60 heures après la date de ce message avant de poster solutions, indices ou autres révélations. Merci. WICHTIG: Bitte schicken Sie keine Lösungen, Tipps oder Hinweise für diese Aufgabe vor Ablauf von 60 Stunden nach dem Datum dieser Mail. Danke. Qing3 Zhu4Yi4: Qing3 Ning2 Deng3Dao4 Jie1Dao4 Ben3 Xin4Xi2 Zhi1Hou4 60 Xiao3Shi2, Zai4 Fa1Biao3 Jie3Da2, Ti2Shi4, Huo4 Qi2Ta1 Hui4 Xie4Lou4 Da2An4 De5 Jian4Yi4. Xie4Xie4. ---------------------------------------------------------------- Write a function, format_number_list, whose argument is a list of integers. It then returns a string which represents the input list in compact, human-readable form. For example, format_number_list(1, 2, 4, 5, 6, 7, 9, 13, 24, 25, 26, 27) will return "1-2, 4-7, 9, 13, 24-27" Also write a function, 'expand_number_list', which does the conversion in the opposite direction, so that expand_number_list("1-2, 4-7, 9, 13, 24-27") will return (1, 2, 4, 5, 6, 7, 9, 13, 24, 25, 26, 27) (Thanks to Mark Hickman for suggesting this quiz problem.)