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.

['8235', 't', '1695', '9899', '3633', 't', '1823', 'r', 'x']
r, t, x

['1649', 'l', 'i', '5901', 'o', 'g', '1197', 'a', '9327', '9835', '1095', 'k', '4489', '9149', 'o', '3095', 'z', 'u', 'y', '561', '7419', 't', 'j', '8763', 'v', '339', 'y', 'w', 'v', 'v', '1867', 'd', 'r', 'w', 'h', 'j', '1531', '3841']
a, d, g, h, i, j, k, l, o, r, t, u, v, w, y, z

['7329', 'q', 's', '8961', 'h', '2609', '5187', 'q', '6511', '9927', 'w', '937', 'l', 'v', '6905', 'j', '1335', '4439', '4779', '2539', '8645']

h, j, l, q, s, v, w