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: ['r', 's', '2471', 'n', '635', 'k', '3551', '7041', '8765', '1221', '8439', '7773', '6471', 'u', 'p', '2093', '6479', '1435', '6881', 'a', 'y', 'm', 'r', '1627', 'w', 'k', 'b', '3095', '9059', '285', 'y', 'a', 'm', 'x', '637', 'i', '3407', 'e', 'e']

Output: a, b, e, i, k, m, n, p, r, s, u, w, x, y


Input: Consider Input: ['l', '1213', 'm', 'k', '7825', '3501', '2397', '2313', 'v', '4119', 'h', 't', '6137', 'l', '9851', 'q', '9661', 'b', 'z', '1437', '1759', 'l', '611', '5085', '4443', 'n', 'u', 'b', '2511', '6023', '7157', 'n', '9921', 'o', 'a', 'o', 'w', 't', 'o', '1607', '6751', 'n', 'b']

Output: a, b, h, k, l, m, n, o, q, t, u, v, w, z


Input: Consider Input: ['3127', '1903', '609', '1965', 'c', 'a']


Output: a, c


