Q: 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.
['4651', 'd', 'h', '1311', '9049', 'w', '7547', '5165', 'q', 'r', '3737', 'g', 'i', 'e', '7255', 's', '3229', 't', 'g', 'r', 'a', '2739', 'l', '179', '97', '5723', '6339', 'e', '3521', '8117', '1019', '2701', '1531', 'w', '3869', '5397', '6975', 'r', '3573', '2521', '789', 'n']
A:
a, d, e, g, h, i, l, n, q, r, s, t, w