Q: 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.
['6869', '5205', '9543', 'q', '3527', '5897', 'i', 'n', '6255', 'f', 'v', 'u', 'c', '9555', '6705', '6339', 'z', '4595', '9425', 'f', '2395', 't', 'c', '7071', '7063', 'p', '5131', '6637', 'o', '2165', '961', '4345', 'd', 'x', 'n', 'g', '6023', '8229', '2157', '861', '1987', 'n', '8901', '6635']
A:
c, d, f, g, i, n, o, p, q, t, u, v, x, z