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.

['s', '2507', '3091', 'g', '7643', '2573', 'w', 'r', '1977', 'q', 'c', 'j', '1335', '9671', '7317', '567', '2041', '5777', 'w', 'm']
c, g, j, m, q, r, s, w

['5785', 'c', 'f', '7087', 'd', '9225', 'm', 'g', '4639', '7165', '3445', '3813', 'p', 'i', '719', 's', 'g', '6423', '9563', 'w', 'm', '8659', '8809', '4105', '3923', '465', '5637', '5547', 'h', 'v', '9453', '4009']
c, d, f, g, h, i, m, p, s, v, w

['4925', '9943', '7935', '4387', '2449', '5797', 'i', '1517', 'w', 'e', '9525', 'y', 't', 'e', '2793', 'v', '9897', '8709', '7247', 'o', 'f', '5549', 'q']

e, f, i, o, q, t, v, w, y