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.

[EX Q]: ['m', '8127', '7519', '4543', '2809', '9855', 'n', '6241', 'w', 'w', 'q', 'w', 'p', '8599', '7819', '3817', 'm', 'q']
[EX A]: m, n, p, q, w

[EX Q]: ['4397', '2685', '9539', '4343', '6697', '7693', 'g', 'c', '3587', '4691', 'j', '8931', '7397', '2103', '3431', 'u', 'l', 's', 'v', 'q', 'd', '1289', 'h', '1695', 'h', 'j', 'e', '1225', 'e', '7893', 'o', 'i', '3351']
[EX A]: c, d, e, g, h, i, j, l, o, q, s, u, v

[EX Q]: ['9551', 'i', '6961', 'b', '557', '9443', '5287', '3423', '2715', '5237', '3223', '4191', 'c', '5067', 'k', 'v', '4183', '1547', '6403', 'b', '3325', '4171', '4719', '527', '8941', '3691', '1763', 'i', 'n', '3407', '3853', '6607', 'j', '173', 't', '9905', '6547', 'r', '995', '5777', 'q', '4905', '5697', 'i']
[EX A]:
b, c, i, j, k, n, q, r, t, v