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.

[EX Q]: ['8527', 'p', '4697', '8415', 'v', 'l', '2669', '2649', '4349', '4201', 'r', '7573', '2041', 'f', '8047', 'u', 'm', 'm', 'j', '5695']
[EX A]: f, j, l, m, p, r, u, v

[EX Q]: ['a', 'w', 'm', 'g', 'c', '5475', '7391', 't', '1049', 'p', 'd', '1397', 'k', 'x', 'j', '2525', 'f', '741']
[EX A]: a, c, d, f, g, j, k, m, p, t, w, x

[EX Q]: ['3517', 'i', 'o', 'f']
[EX A]:
f, i, o