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.

Q: ['d', '1625']

A: d
****
Q: ['p', '2923', 'e', 'k', '5433', '605', '5079', 'k', 'p', 'x', '4845', '4099', '6795']

A: e, k, p, x
****
Q: ['i', '217', 'o', '9005', '1717', '9573', 'q', 'z', '6113', '8519', '5795', 'b', '6467', '8685', '6203', 'm', '2827', '1917', '8889', 'a', 'x', 'y', 'q']

A:
a, b, i, m, o, q, x, y, z
****