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.
--------
Question: ['h', 'g', '4563', 'v', 'm', '107']

Answer: g, h, m, v


Question: ['f', 'j', '9195', '3155', '2855', '5333', '5263', '9279', '687', 'e', '3055', '7233', '13', 'j', 'p', 'i', '8327', 'm', 'h', '3977', 'h', '7997', 'a', 'h', '4661', 'x', '8237', 'a', '5009', 'o', 'p', 'z', '2293', 'q', 'p', '5469', 'k', 'q', 'b', 'n', '1967', '4991']

Answer: a, b, e, f, h, i, j, k, m, n, o, p, q, x, z


Question: ['v', 'a', '3367', 'z', '7245', 'o', '67', '4113', 'o', '9925', '7771', 'n', '1699', 'g', 'o', 'd', 'f', 'n', '509', '9123', '135', 'f', 'i', '8447']

Answer:
a, d, f, g, i, n, o, v, z