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: ['477', '3931', 'g', '5967', 'm', '9845', '1607', 'a', '1749', 'k', 'j', '7945', '9125', 'v', 'n', 's', '5185', '1117', '17', 'x', '4149']

A: a, g, j, k, m, n, s, v, x
****
Q: ['2293', 'p', '9787', '7241', '8689', 'u', '3141', 'h', 'c', 'b', 'f', 's', '319', 'c', 'p', '6909', 'p', 'f', '1717', 'd', '2285', 's']

A: b, c, d, f, h, p, s, u
****
Q: ['8467', 'k', 'w', 'y', '3747', 'l', '8691', 'r', 'o', '6041', 'l', 'q', 'u', '7001', 'j', 'z', '1007', 'x', '2205', 'e', '6613', 'e', '2725', '9655', 'q', 'f', '9687']

A:
e, f, j, k, l, o, q, r, u, w, x, y, z
****