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.

Input: Consider Input: ['r', 's', '3409', 'a', 'e', '6855', 'i', 'n', '8655', 's', 't', '8401', 'u', '9603', '8815', 'q', 'a', 'x', 'i', '8455', 'e', '5877', '3917', 'p']

Output: a, e, i, n, p, q, r, s, t, u, x


Input: Consider Input: ['4045', '4739', 'd', 'e', '6789', 'e', 'q', '4909', '9511', 'h', '9543', '6725', 'a', '3683', 'q', 'k', 'd', 'q', 'z', 'b', '3245', '9877', '9155', '7751', 'e', '1015', '2379', 'f', 'y', '1121', '9801', 'c', 'h', 'l', 'f', '67', 'v', 'v', 'y', 'c', '3871', 'v', '5893', 'a']

Output: a, b, c, d, e, f, h, k, l, q, v, y, z


Input: Consider Input: ['3837', '3061']


Output: -1