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.

[EX Q]: ['1449', 'a', '6261', '303', '4651', 'n', 'u', '1595']
[EX A]: a, n, u

[EX Q]: ['8451', 'x', '9965', '9303', 'm', 'f', '4205', 'y', 'n', '8521', '9995', 'z', 's', '3519', 'k', 'e', 'o', 'k', '9611', 'q', 'l', 'p', '3339', '4023', 'n', 'd', '8903', 'a', 'k', 'u', '4009', 'e', 'm', '989', '4495']
[EX A]: a, d, e, f, k, l, m, n, o, p, q, s, u, x, y, z

[EX Q]: ['e', '2933', 'a', '323', 'o', 'o', '6575', 'g', '7471', 'x', '3721', '3399', 'q', '2669', '1745', '3793', '3055', '5533', 'a', '6707', 'w', '5367', 'd', '3597', '2641', '5613', 'e', '2825', '3871', '4195', '9793', 'g', '9271', '4745', '3989']
[EX A]:
a, d, e, g, o, q, w, x