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.
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Question: ['r', 't', '3539', 'z', 't', '6055', 'r', '5787', '8469', 'p', 'h', '9729', 'z', '1637', '5873', 'c', '3597', '4411', 's', 'k', 'q', '6471', '5375', 'e', 'v', 'i', '7425', 'h', '9079', 'd', '1585', '6011', 'x', '5669', '5219', '4951', '4765', '8285', '2811', 'c', '1805', '6463']

Answer: c, d, e, h, i, k, p, q, r, s, t, v, x, z


Question: ['1649', 'l', 'i', '5901', 'o', 'g', '1197', 'a', '9327', '9835', '1095', 'k', '4489', '9149', 'o', '3095', 'z', 'u', 'y', '561', '7419', 't', 'j', '8763', 'v', '339', 'y', 'w', 'v', 'v', '1867', 'd', 'r', 'w', 'h', 'j', '1531', '3841']

Answer: a, d, g, h, i, j, k, l, o, r, t, u, v, w, y, z


Question: ['p', '8327', '4067', '9485', 'd', 'z', '883', '5413', 'g', 'c', '1189', 'f', '8263', 'd', '4303', 't', 'd', '9387', '2837', 'g', 'm', 'w', 'b', 'f', 'o', '8493', '3503', 'e', '71', 'h', 'y', '9559', '719', 'w', '5055', 'v', 'p', '8855', 'u', '7773', '45', 'd', 'k', 'k', '9861']

Answer:
b, c, d, e, f, g, h, k, m, o, p, t, u, v, w, y, z