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.

['l', 'g', 'd', 'p', '8163', '6643', 'o', 'p', 'm']
d, g, l, m, o, p

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

['3909', 'o', 'y', 'f', 't', 'u', 'c', '3715']

c, f, o, t, u, y