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:
['57', 'j', 'n', '877', 'u', 'w', 'j', 'f', '8977', 'h', '469', '9417']

Ex Output:
f, h, j, n, u, w


Ex Input:
['2705', 'n', 'r', '8259', '6839', '3239', 'w', 'z', '2611', '2957', '2303', '6315', '7801', 'c', 'w', 'm', '5049', '6465', '599', 'h', 'q', '7559', 'n', '9917', 'v', 'l', '643', '6415', '3587', 'c', '917', '4435', 'p', 'a', '317']

Ex Output:
a, c, h, l, m, n, p, q, r, v, w, z


Ex Input:
['u', 'z', '9143', 'f', 'o', 'g', 'f', 'v', 'v', '2589', '2525', 'c', '5283', 'x', '2355', 'm', '6997', '6167', 'd', 'r', 'c', 'j', '7429', 'r', '1629', '9637', '8593', 'a', 'f', '8845', '2687', '4183', '6365', '6979', '2409', 'b', 'j', 'o', 'r', 't', '7785', 'l', 'f']

Ex Output:

a, b, c, d, f, g, j, l, m, o, r, t, u, v, x, z