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]: ['s', 'w', '8949', '4025']
[A]: s, w


[Q]: ['s', 'j', '6779', '1535', 'd', 'e', 'u', '3023', '241', '9115', 'h', '8003', '3755', 'q', 'm', '2725', 'x', 'y', 'n', 'm', 'j']
[A]: d, e, h, j, m, n, q, s, u, x, y


[Q]: ['2301', '179', '2433', '7599', '5009', 't', '6547', '8329', '8351', '6823', '4417', '9605', '8523', '79', 'g', 'a', '6635', '7045', 'i', 'q', '7785', 'j', '2123', '5351', 'o', '1969', '7175', 'u', 'z', 'i', '8369', 'm', '6965', '2315', '6707', '3443', '9617', '8135', 'f']
[A]:
a, f, g, i, j, m, o, q, t, u, z