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]: ['6175', '9441', '7127', '5979', 's', '1367', 'e', 'm', '7083', '1787', '8375', '2851', '3475', 'r', '697', 'g', 'z', 'm', '4207', 'c', '7971', 'z', '9339', 'd', 's', '3507', '9003', 'i', 'y', 'w', 'j', 'i']
[A]: c, d, e, g, i, j, m, r, s, w, y, z


[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]: ['2801', '6545', 'r', 'e', '723', 'a', '5993', 'u', '947', '8501', 's', 'w', '4233', '5111', 'i', 'h', '691', '3765', '9029', '5929', 'o']
[A]:
a, e, h, i, o, r, s, u, w