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: ['8301', 'd', 'p', 'l', 'm', '9099', 'o', '8045', 'e', 's', 't', '8853', 'v', '6375', 'q', '2505', 's', '4219', '3587', 'g', '651', '7129']

Answer: d, e, g, l, m, o, p, q, s, t, v


Question: ['h', 'b', '9601', 'h', 'h', 'h', '8099', '8265', 'i', 'd', '8791', 'p', '8059', '4309', '501', '2581', '9837', '157', '4785', '5925', 'q', '8491', '4779', 'r', 'l', 'k', '3679', 'v', 'g', 'g', '9731', '1909', '9783', 'f', '4293', '5009', 'o', '3057', '3157', 'c', '5587', 'b', 'f', 'd', 'k']

Answer: b, c, d, f, g, h, i, k, l, o, p, q, r, v


Question: ['8069', 'v', 'h', '9651', 'n', '6495', '3623', 'b', 'd', 'r', '7671', 'q', '57', 'm', '4041', 'p', '9055', 'a', 'u', '7679', 'k', '1151', 'e', 'x', 'g', 'o', 'u', 'i', '1889', 'p']

Answer:
a, b, d, e, g, h, i, k, m, n, o, p, q, r, u, v, x