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:
['w', 'o', 'l', '5331', 'k', '9325', '6759', '7931', '8185', 'w', 'h', 'h', 'x', '4357', '6845', 'v', 'o', '8401', 'u', 'g', 'f', 'j', 'j', '2493', '4753', 'c', 'm', '1469', '4307', 'm', '2737', 'n', 'y']
answer:
c, f, g, h, j, k, l, m, n, o, u, v, w, x, y


question:
['z', 'h', '2065', '6773', 'v', '151', '8957', 't', 'l', 'j', '7867', 'v', '799', '9009', '4317', 'm', '6921', 'r', '1245', '5637', 'x', '4465', 'f', 'y', '3549', 'e', 'f', 'm', 't', '6281', '4241', '3415', 'z', 'g']
answer:
e, f, g, h, j, l, m, r, t, v, x, y, z


question:
['4843', '1403', '9983', '9043', 'z', 'f', 'q', '8721', '6567', 'r', 'n', 'n', 'v', '6509', '3', 'k', 'c', '5725', 'w', 'r', '1483', '8209', 'a', 'y', 'w', '9927', 'x', 'n', 'x', '1225', '7453', 'g', 'n', 'm', '7607', '7459', 'r', '3855', '5753', 't', 'y', '9159', 'z', '6553', 'c']
answer:

a, c, f, g, k, m, n, q, r, t, v, w, x, y, z


