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]: ['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']
[EX A]: c, d, e, g, i, j, m, r, s, w, y, z

[EX Q]: ['c', 'h', '8655', 'r', '7531', 's', 'r', 'w', 'e', 's', 'p', '1709', '5447', 'b', '5855', 'w', 'f', 'i', '7809', 'q', '1975', 'z', '4037', 'k', 'l', 'z', 'g', '9739', '8801', '3405', '6549', '4561', 'd', '1669']
[EX A]: b, c, d, e, f, g, h, i, k, l, p, q, r, s, w, z

[EX Q]: ['j', 't', '2655', '7511', '7123', '3845', 'd', '5219', 'y', '3213', '5919', '4351', 's', 'u', '9361', '3513', '7025', '8751', 't', 'c', 'e', 'o', 'r', 'k', 'l', '2105', '5351', 'd', 'g', '4177', '6875', '3891', '1713', '9939', '2453', '6937', 'w', '961', 'm', 'k']
[EX A]:
c, d, e, g, j, k, l, m, o, r, s, t, u, w, y