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: ['1447', 'q', '9529', '2971', 's', '7351', '6753', '3493', 'v', 'c', 'x', '3097', '9145', 'b', 'e', 'b', '2967', '6933', 'e', 's', 'v', 'f', 'z', 'r']

Output: b, c, e, f, q, r, s, v, x, z


Input: Consider Input: ['2521', '8027', 'm', '193', '615', 'l', '1947', '5949', '6307', 'r', '1015', '743', 'v', '6949', 'b', 'g', '8841', 'c', 'b', '2879']

Output: b, c, g, l, m, r, v


Input: Consider Input: ['b', '2729', '253', 'm', 's', 'f']


Output: b, f, m, s