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:
['7123', 'm', 'h', '4065', 'c', 'n', '187', '3899', 'r', 'k', '2071', '9481', '6277']

Ex Output:
c, h, k, m, n, r


Ex Input:
['w', 'o', 'l', '5331', 'k', '9325', '6759', '7931', '8185', 'w', 'h', 'h', 'x', '4357', '6845', 'v', 'o', '8401', 'u', 'g', 'f', 'j', 'j', '2493', '4753', 'c', 'm', '1469', '4307', 'm', '2737', 'n', 'y']

Ex Output:
c, f, g, h, j, k, l, m, n, o, u, v, w, x, y


Ex Input:
['1811', 'q', 'l', '5599', 'v', 'p', 'l', 'n', 'a', 'o', '7535', '6143', '9533', 'x', 't']

Ex Output:

a, l, n, o, p, q, t, v, x