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.

['j', '917', 'w', 't', '8873', '1431', '8059', '7041']
j, t, w

['l', '6819', '1029', '2925', '2361', '5545', '2151', '2681', 'f', 'p', '1263', '2875', 'b', '4665', 'f', 'g', 'p', '4829', '8453', 'z', 'l', '4219', '7517', '25', 'a', '5099', '3693', 'i', '1815', '1541', 'g', '7665']
a, b, f, g, i, l, p, z

['4297', 'w', 'd', 'f', '9277', 'x', 'd', '8005', '4193', 'r', '7473', '9357', 'l', '4455', 'l', 'l', 'u', '847']

d, f, l, r, u, w, x