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]: ['2521', '8027', 'm', '193', '615', 'l', '1947', '5949', '6307', 'r', '1015', '743', 'v', '6949', 'b', 'g', '8841', 'c', 'b', '2879']
[A]: b, c, g, l, m, r, v


[Q]: ['3035', 'f', 'k', 'e', '3023', 'p', '9667', '5277', '4757', '8433', 'g', '1399', '7721', 'n', 'p', '7469', '7581', '5679', 'g', 'q']
[A]: e, f, g, k, n, p, q


[Q]: ['5239', '2989', '5059', '2745', '3533', 'k', 'j', '6923', 'i', '1783', '3311', 'a', '3567', '5739', 't', '1505', '6533', 's', 'i', 'h']
[A]:
a, h, i, j, k, s, t