instruction:
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.
question:
['3627', '2051', '3203', 'c', 'r', 'a', '1453', 'e', 'z', 't', '1093', '4651', 'a', 'f', '8159', '9623', 'l', 't', 'r', '6963', '7071', '8103', '3493', 'y', '2369', '609', '2011', 'f', '187', 'f', 'c']
answer:
a, c, e, f, l, r, t, y, z


question:
['5973', 'h', '4081', 'i', '8059', 'w', 'j', '6175', 'w', '8685', '5811', 'k', 'n', '5577', '9817', 'v', '8617', 'u', 'y', '3921', 'b', '1027', '5405', 'a', '3501', '6659', 's', 'e', '157']
answer:
a, b, e, h, i, j, k, n, s, u, v, w, y


question:
['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']
answer:

b, c, i, j, k, n, q, r, t, v