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]: ['i', '4447', 'g', 'o', 'j', 'p', 'l', 'q', 'o', '8777', 'r', 'v', '961', '6083']
[A]: g, i, j, l, o, p, q, r, v


[Q]: ['5161', 'v', 'y', '6005', 'y', 'l', '5451', 'z', 'j', 'd', '4597', '9319', '1241', 'g', 'f', 'b', 'g', '683', '763', 'm']
[A]: b, d, f, g, j, l, m, v, y, z


[Q]: ['l', 'w', 'n', '443', 'l', 's', '253', '7171', '9951', 's', 'c', '8847', 'l', '3915', 's', 'c', '75', 'n']
[A]:
c, l, n, s, w