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.

['l', 'i']
i, l

['6599', 'f', 'c', '661', 'q', 'e', '1951', 'f', 'f', 'a', 'd', '9521', '853', 'n', 'w', '6451', '5549', 'k', 't', 'l', 'z', 'm', 'k', '567']
a, c, d, e, f, k, l, m, n, q, t, w, z

['4129', 'a', 'p', 'h', '6425', 'n', '5217', 'p', '2761', 'f', '221', 'c', 'j', '1701', '795', '4943', 'r', 'v', 'w', 'f', '1137', 'c', '4031', 'v', '3553', 'w', 'a', 'g', 'j', 't', '9049', 't', 'm', '7375', '6607', '2183', '275', '2859', '1773', '9599', 'e', 'm', '8237']

a, c, e, f, g, h, j, m, n, p, r, t, v, w