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: ['t', 'h', '6141', 'g', 'f', 'z', 'n', 'b', 'k', '9059', 'y', 'p', '4289', '2683', 'a', '3267', 'w', 'p', 't', '3623', '7759', 'a', 'o', 'm', '9815', 'q', 'u', '8051', '6871']

A: a, b, f, g, h, k, m, n, o, p, q, t, u, w, y, z
****
Q: ['7591', '7521', 'm', '1429', 'x']

A: m, x
****
Q: ['r', 'l', 'h', '2943', '5649', '7019', 'n', '4233', '9927', '3215', 'x', '4445', 'k', 'a', 's', '9519', 'p', '5035', '8263', '2871', 'd', '7271', '3705', '6979', 'e', '5425', '9011', '5265', '9633', '4403', 'u', '1561', 'o', 'n', 'z', '1401', '6923', '7007']

A:
a, d, e, h, k, l, n, o, p, r, s, u, x, z
****