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: ['c', 'e', '6509', '1295', 'u', '5445', '1731', '3049']

A: c, e, u
****
Q: ['163', 'x', 'g', '5997', 'm', 'l', '7225', '7907', '375', 'y', 'a', 'j', 'c', 'j', '7755', '147', 'h', '3845', 'y', 's', 'h', 'u', '8737', '6091', 'j', 'f', 'c', '7395', '881', '1771', 'y', '3691', 'h']

A: a, c, f, g, h, j, l, m, s, u, x, y
****
Q: ['5249', '2637', '6263', 'g', 'i', '9671', '475', 's', 'x', 'p', '7243', '8019', 'g', 'k', '2671', '3369', '5749', 'b', '8813', '1027', 'p', '6023', '9193', 'l', 'u', '5427', '6941', '1087', 's', 'b']

A:
b, g, i, k, l, p, s, u, x
****