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.

['h', '6865', '4019', '8571', 'y', '5575', '7835', '9537', 'n', '875', 't', 'a', 's', '2769', 'p', '1607', 'n', '4087', '961', '7869', '5085', '2131', '4867', 'j', 'h', 'y', '3105', '6609', 's', 'l', '3399', '5013']
a, h, j, l, n, p, s, t, y

['7071', 'h', '837', 'z', 'c', '2217', 'c', '6341', '6607', 'g', '3569', 'a', 'h', 't', 'b', 'f', 'g', 'f', 'l', 'b', 'x', 'o', 'r', '8949', '8071', '1507', 'v']
a, b, c, f, g, h, l, o, r, t, v, x, z

['j', 'g', '7589', 'v', 's']

g, j, s, v