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]: ['d', '4377', '9271', '8053', '9519']
[EX A]: d

[EX Q]: ['5859', 'x', 'z', 'v', 'l', 'z', 'g', 't', 'x', '341', '7023', '4937', 'b', 'n', 'y', 't', 's', '1369', '4461', 'f', '1315', 'l', '5221', '6583', 'h', 'j', 't']
[EX A]: b, f, g, h, j, l, n, s, t, v, x, y, z

[EX Q]: ['6469', '7001', 'c', 's', 'f', 'g', 'v', '917']
[EX A]:
c, f, g, s, v