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.

['f', '165', 'm', '9975', '9259', '6505', 'a', 'g', 's', '1127', 'h', 'n', 'c', '6475', 'c', '8657', 'a', '4057', 'm', 'y', 'w', 'm', '6567', '7297', '285']
a, c, f, g, h, m, n, s, w, y

['n', 'h', 'j', '5945', '8511', 'y', '7739', '4717', '2483', 'p', '9545', '7647', '9863', '5591', '5393', 'i', '9225', '589', '1497', 'j', 'm', '2397', 'a', 'd']
a, d, h, i, j, m, n, p, y

['n', '6731', '5405', 'v', 'g', 'o', '9631', '6931', 'b', 'n', 'w', '2061', '4021', '1201', 'l', 'w', 'g', '8581', 'i', 'm', '4401', '2797', 'r', '7477', '8337', '3839', '7479', 'z', '4801', 'k', 'o', '2725', 'k', 'l', '6343', '2635', '4959', '9633', '8139', 'y', 'm', 'd', '115', '4061', 'h']

b, d, g, h, i, k, l, m, n, o, r, v, w, y, z