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.

['6737', 'g', '9985', '5257', 'k', 't', '7863', 'y', '8319', 'l', 'o', '6505', '6531', 'z', '3055', '2943', '3625', 'h', '4867']
g, h, k, l, o, t, y, z

['n', 'y', '7087', '9539', 'x', 'i', 'w', '7237', '8613', 'k', '5999', '4179', 'o', 'm', '7485', '1955', 'w', '1451', 'h']
h, i, k, m, n, o, w, x, y

['g', 'g', 'h', '5305', 'd', '6333', '5055', '4621', '1441', '5199', 'l', 'a', 't', '2441', '1283', 'u', '1253', 'r', '2565', '9655', '5797', 'e', '3063', '1017', '439', '3427', '5319', 'q', 'i', '8459', '9811', 'w', 'g', 't', '8027', '8783', '5771', 'j', 'f', 'k']

a, d, e, f, g, h, i, j, k, l, q, r, t, u, w