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.

['5075', '9169', '4659', '7605']
-1

['3821', '385', 'y', '8457', '6623', 'g', '5923', 'a', '7193', 'v', 'm', '8915', 'v', '5873', 'p', 't', 'w', 'y', '3617', 'h', 'w', 'j', '8047', 'u', '2271', 'v', 'a', '2181', 's', '1051', 'b', 'a', '9967', '987', 'z', '2255', '6349', '1249', '1397', 'q']
a, b, g, h, j, m, p, q, s, t, u, v, w, y, z

['9351', '9271', 'e', 'r', 'h', '7753', '6943', '3067', 'g', '3581', '8667', '1019', 'f', '4527', 'v', 'f', 'f', '7751', 'i', 'r', 'u', 'k', '3407', '5065', 'b', '8563', 'b', 'm', 'g', 'n', '4527', '7457', '3471', 'v', 'o', '3641', '8971', '4181', '7595']

b, e, f, g, h, i, k, m, n, o, r, u, v