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.

Example Input: ['4787', 'c', '1727', '9863', '8147', '3931', 'b', '1133', '3023', '7427', '7837', 'n', '7921', 'o', 'c', '3973', '1949', 'x', 'g', 'b', 'd', '8559', '8661', '4465', 'z', '369', 'q', 'e', 'y', '8629', '7665', 'i', 'r', 'n', 'z', '9115', '1393', '4899']
Example Output: b, c, d, e, g, i, n, o, q, r, x, y, z

Example Input: ['o', '369', 'z', '5721', 'w', 'v', '4973', '7773', 'k', '3071', '5103', '425', '4239', '7977', 'n', 'i', 'k', '8117', '9843', 'n', 'd', '1353', 'h', 'd', 'v', 'z', 'j', '8727', '6997', 'x', '767', '4331', 't']
Example Output: d, h, i, j, k, n, o, t, v, w, x, z

Example Input: ['z', '7059', '4803', 'c', 'h', 'r', '9761', 'j', '9311', 'm', '4653', 'p', 'z', 'y', 'c', 'b', '6175', 'v', 'f', 'm', '6565', 'd', '8803', '1983', '3927', '9765', '1943', 'n', '1381', '8423', '2201', '6955', '1889']
Example Output:
b, c, d, f, h, j, m, n, p, r, v, y, z