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.

Q: ['3797', '6117', 'x']

A: x
****
Q: ['f', '217', '449', 't', 'j', '4097', '5561', '8317', '647', 'u', 'b', '7833', 'r', '9011', 'z', '2753', '2183', 'z', 'o', 'g', '7541', 'b', '8795', '327', 'v', 'e', 't', 'l', '4909', 'k', '7681', 'r']

A: b, e, f, g, j, k, l, o, r, t, u, v, z
****
Q: ['p', '857', 'd', 'g', 'c', '5451', 't', 'c', 'h', 'm', '9567', '7841', 's', '9649', 'p', 'g', '2635', '3655', '1513', 'v', '6873', '5237', 'q', '3045', '159', 'c']

A:
c, d, g, h, m, p, q, s, t, v
****