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: ['5553', 'f', '3881', '8867', 's', 'd', 'a', '375', '7889', '3949', '2905', 'w', 'q', 'q', 'd', '4203', 'i', '2601', 'y', 'p', 'k']

Answer: a, d, f, i, k, p, q, s, w, y


Question: ['3307', 'r', '2665', '3453', 'f', 'd', 'v', '3801', '3153', '3137', 'y', 'i', '9681', 'k', '9253', 'y', 'i', '8631', '2375', '5131', 'r', 'z', '8645', '595', 's', '6749', '2665', '709', '8203']

Answer: d, f, i, k, r, s, v, y, z


Question: ['q', 's', '3485', 'm', '7283', 'a', '4847', '3035', '6037', '2233', 'z', 'o', '4295', '4569', '1', 'h', '4403', 'j', 'b', '6241', '6393']

Answer:
a, b, h, j, m, o, q, s, z