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: ['333', 'b', '261', 'k', 'p', '7861']

Output: b, k, p


Input: Consider Input: ['o', 'h', 'z', 'n', 'e', 'y', 't', '4371', 'm', '1059', '4853', '8529', 'l']

Output: e, h, l, m, n, o, t, y, z


Input: Consider Input: ['k', 'l', '6901', 'm', '95', '4045', '6369', '2713', 'n', '5871', 's', '6307', '7887', 'v', 'v', '995', 'q', 'd', '1657', 'k']


Output: d, k, l, m, n, q, s, v