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]: ['1595', '2915', 'o', 't', 'c', 'h', '3969', '5407']
[A]: c, h, o, t


[Q]: ['6697', 'j', '1571', '4989', 'o', '1143', 'i', '2969', '2541', '4899', 'i', '4751', 'n', 'b', '801', '4357', '3855', '49', 'm', '211', '7281', '121', '5231', '8313', '8967', '8043', '7699', 'r', '4315', '8637', '3339', '4437']
[A]: b, i, j, m, n, o, r


[Q]: ['m', 'w', '6453', 'x', 'r', '935', '4503', '6479', 'k', '611', 'r', '7141', 'v', '9089', 'n', 'z', '9307', '5123', '1563', 'c', 'x', 'k', 'x', '6463', '9729', '8907', '6027', 'l', '6687', '1197', '7091', 'q', '1901', 'u', 't', '7735', 'v', 'e', '1669', '3111']
[A]:
c, e, k, l, m, n, q, r, t, u, v, w, x, z