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: ['u', '4731', 'l', 'p', '1997', '601', 'n', 'l', 'p', '211', '7355', '6537', 'w', 'x', '1741', '8145', '3689', 'm', 'y', '6945']

A: l, m, n, p, u, w, x, y
****
Q: ['k', '1995', 'b', '2581', 'x', '2639', 'i', '6761', '2701', 'd', '6993', '9375', 'r', 'm', '249', '8115', '8179', 't', '4901', 'i', '6197', '2809', 'e', 's', 'j', '4261', 'f', '6649', '7527', '3839', '5651', '9287', 'n', '2505', 's', 'q', '2825', 'g']

A: b, d, e, f, g, i, j, k, m, n, q, r, s, t, x
****
Q: ['3711', '9573', 'b', '389', '9693', 'g', '1175', '5493', 't', '3443', 'y', 'd', '5113', '2015', 'o', 'v', '9605', '2607', 'o', 'p', '1043', 'r', '1687', 'q', '3235', '7011', 's', '1367', 'w', 'p', 's', 's', 'y', 'd', '8043', 'w', 'l', '783', '695', '6071', '3393', 'h', '8661']

A:
b, d, g, h, l, o, p, q, r, s, t, v, w, y
****