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: ['r', 's', '3409', 'a', 'e', '6855', 'i', 'n', '8655', 's', 't', '8401', 'u', '9603', '8815', 'q', 'a', 'x', 'i', '8455', 'e', '5877', '3917', 'p']

A: a, e, i, n, p, q, r, s, t, u, x
****
Q: ['q', '6421', 'w', 'x', '669', 'h', '3853', '6609', 'p', '947', 'g', 'c', 'x', '2617', 'v', 'e', '4795', '5755', 'a', '2379', 'y', '5939', 'l', 'h', 'g', '3779', 'c', 'm', '3157', '4027', 'g', '2917', '9461', '7271', 't', 'i', '9807', '147']

A: a, c, e, g, h, i, l, m, p, q, t, v, w, x, y
****
Q: ['u', 'q', 'l', 'h', '7137', '9205', '5553', '843', '4451', 'i', '8171', 'u', '425', 'd', '2817', 'j', 'b', 'f', 'z', 'c', '711', '2399', '5453', '1491', 'p', '9071', '4023', '6663', '3651', 'z', '3569', 'd', 'i', 'o']

A:
b, c, d, f, h, i, j, l, o, p, q, u, z
****