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.

Input: Consider Input: ['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']

Output: a, b, c, f, g, h, l, o, r, t, v, x, z


Input: Consider Input: ['895', '2049', '8839', '1773', 'v', '467']

Output: v


Input: Consider Input: ['i', '6373', 't', '4891', '1127', '6561', '4391', 'h', '5879', '6739', 'r', '3969', '4447', 'h']


Output: h, i, r, t