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: ['s', 'w', '8949', '4025']

A: s, w
****
Q: ['j', '6675', 'u', 's', '705', '8227', 'f', 'w', 'n']

A: f, j, n, s, u, w
****
Q: ['t', 'x', '6825', 'm', '2299', '225', '3095', '8701', '6953', 'u', '8835', 'h', 'u', '7477', '3335', 'i', '4587', '2671', '69', '4923', 'q', '4799', 'b', 'g', 'a', '953', 'l', '3949', 'd', '9197', 'e']

A:
a, b, d, e, g, h, i, l, m, q, t, u, x
****