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:
['5039', '2227', 't', 'o', '3313', 'm', 'v', '637', '6773', 'v', 'c', 'l', 'y', 'u', '3823', '9669', 'k', 'h', '3589', 'b', 'i', '3833', 's', 'm', '8201', 'u', '3143', 'k', '4111', '9769', '425', '4339', '209', 'c', 'c', '669', '8201', 'u', '7443', '2387', '6919', 'b', 'b', '2873']

Ex Output:
b, c, h, i, k, l, m, o, s, t, u, v, y


Ex Input:
['5159', '6407', '4021', '6655', 'c', 'k', 'w', '7191', 'l', '4321', '1609', 'm', '1991', '9261', '511', 'p', '7495', 'b', 'e', '4647', '2711', 'd', 'y', '3835', '5037', '3613', '2695', '3367', 'm', 'j', 'y', '9561', '4889', 'a', 'z', '2253', 'p', 't', 's', '8371', '2859', 's']

Ex Output:
a, b, c, d, e, j, k, l, m, p, s, t, w, y, z


Ex Input:
['n', 'h', '9735', 'p', '5515', '4039', 'y', '3737', '7391', 'u', '5609', 'x', 'w', '2317', '2939', '6587', 'c', '7095', 'y', '5403', 'm', 'm']

Ex Output:

c, h, m, n, p, u, w, x, y