In this task, you are given an input list A comprising of numbers and alphabets. You need to extract and sort the unique alphabets in the list. The alphabets in the input list will only be in lowercase. Return -1 if there is no alphabet in the input list.
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Question: ['2799', '7519', '345', 'e', 'l', '9369', '4703', '4111']

Answer: e, l


Question: ['3743', '765', '5299', '3069', '8547', '8991', '1811', 'k', '5557', '4907', '5907', 'd', 'r', 'z', '5385', '5463', 'f', '2063', 'm', '3419', 'k', '3897', '4049']

Answer: d, f, k, m, r, z


Question: ['6317', 'u', 'h', '6441', 'j', '9159', '501', '8751', '1291', '9273', '51']

Answer:
h, j, u