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.

[EX Q]: ['2453', 'r', 'd', '8499', 't', 's', 'h', 'a', 'm', '9271', 'g', '2599', '6209', 'o', 'i', '4069', 't', '6793', '7679', '6643', '7359', 'm', 'f', 'w', '775', '3347', '6161', '9745', 'i']
[EX A]: a, d, f, g, h, i, m, o, r, s, t, w

[EX Q]: ['3947', '4809', 'b', 'a', '4769', '4179', '535', '5965', 'f', 'j', '2265', 'w', '3103', 'u']
[EX A]: a, b, f, j, u, w

[EX Q]: ['f', '359', 'y', '5239', '6675', '9871', '7569', '2145', 'z', 'e', 'f', '5221', 'p', '6921', 'v', 'l']
[EX A]:
e, f, l, p, v, y, z