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 Input:
['2293', 'p', '9787', '7241', '8689', 'u', '3141', 'h', 'c', 'b', 'f', 's', '319', 'c', 'p', '6909', 'p', 'f', '1717', 'd', '2285', 's']

Ex Output:
b, c, d, f, h, p, s, u


Ex Input:
['8051', 'h', 'g', 's', 't', 'p', 'w', 'x', 's', '8521', 'm', '9719', 'j', 'n', 'i']

Ex Output:
g, h, i, j, m, n, p, s, t, w, x


Ex Input:
['9753', 'l', 'h']

Ex Output:

h, l