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.

[Q]: ['6643', '6757', 'h', '1033', 's', 'c', '2003', 'p', '5483', 'f']
[A]: c, f, h, p, s


[Q]: ['1979', 'b', 't', '1101', '7953', '2451', '7539', '6833', 'u', '49']
[A]: b, t, u


[Q]: ['1223', 'h', 'a', 'o', 'v', '2535', 'g', '6267', 'w', '9625', '7961', '9577', '7611', '5655', 'p', 'j', 's', '2141', '4101', 'l', '4367', '9383', 'n', '5965', '9097', '7571', 'p', 'u', 'x']
[A]:
a, g, h, j, l, n, o, p, s, u, v, w, x