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: ['7591', '7521', 'm', '1429', 'x']

Output: m, x


Input: Consider Input: ['8739', 'v', 'm', '6277', 'l', 's', '109', '8057', '3835', 'd', 'u', 'f', 'w', 'd', 'p', '7705', '3643', '4455', 'u', 'p', 'u', '9407', 'g', 'w', '595', 'z', '6827', '6879', 'w', 'w', '6973', 'm', 'e', '1553', 'v', '3529', '8953', '3903', '5713', '8249', 'e', '1113', 'b', 't', 'r']

Output: b, d, e, f, g, l, m, p, r, s, t, u, v, w, z


Input: Consider Input: ['b', '7919', '7867', 'b', 'e', '3079', '2433', 't', '3487', '7949', 'v', 'k', '6931', 't', '6449', '2733', 'r', '6537', '4247', '2843', 'g', '6893', '3143', '73', '8587', 'j', 'g', '9473']


Output: b, e, g, j, k, r, t, v