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: ['o', '9599']

Answer: o


Question: ['q', '9033', 'p', 'z', '1743', '247', '967', '445', '9849', 'f', '9113', 'b', 'g', '6041', 'j', '927', 'i', 'p', '6821', 'q', '6701', 'f', 'j', 'o', 'y', 'c', '7981', 'b']

Answer: b, c, f, g, i, j, o, p, q, y, z


Question: ['d', '445', '9081', '9673', 'v', '4073', 'b', 'l', 'i', 'z', '5003', '4895', 'm', '2959']

Answer:
b, d, i, l, m, v, z


