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 Input:
['s', 'w', 'c', '4137', 't', '2437', '349', 'h', '4539', 't', 'b', 'y', 'q', 't', '9087', 'c', '9489', '6285', '6247', '8353', 'n', 't', '8661', 'p', 'z', 'p', '773', 'w', 'q', '8081', 'r', 'u', 'z', 'k', 'a', 'b', '7513', '5549', '5325', '1101', 's', '6507', '3317']

Ex Output:
a, b, c, h, k, n, p, q, r, s, t, u, w, y, z


Ex Input:
['k', '1995', 'b', '2581', 'x', '2639', 'i', '6761', '2701', 'd', '6993', '9375', 'r', 'm', '249', '8115', '8179', 't', '4901', 'i', '6197', '2809', 'e', 's', 'j', '4261', 'f', '6649', '7527', '3839', '5651', '9287', 'n', '2505', 's', 'q', '2825', 'g']

Ex Output:
b, d, e, f, g, i, j, k, m, n, q, r, s, t, x


Ex Input:
['2489', '4709', '255', '1467', 't', 'd', 'a', '7625', 'z', '8943', '3681', 'b', '6393', '9995', 'h', 'k', 'p', 'f', '7629', 'd', '6327', '7065', '9405', 'u', '9385', '3695', '4339', '5341', 'r', '361', '9059', 'v', 'n', '2887', 'k', '4631', 'g']

Ex Output:

a, b, d, f, g, h, k, n, p, r, t, u, v, z