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.
One example: ['8129', 'a', '4245', 'y', 'm', 'a']
Solution is here: a, m, y
Explanation: Here, the unique alphabets in the list are 'a', 'y', and 'm', hence their sorted order is 'a, m, y'.

Now, solve this: ['h', 'o', '833', 'w', 'c', '6725', 'd', 'v', 'e', 't', 'x', '3193', '2235', '1731', '3349', 'i', '9123', '2643', 'k', '2605', '4997', 'b', '7923', '689', 'm', '861', 'z', 'b', 'k', 's', 'p', 'u', 'q', 'l', 'p', '8423', 'c', '4451', 'q', '6241', 'f', '9803', '5441']
Solution:
b, c, d, e, f, h, i, k, l, m, o, p, q, s, t, u, v, w, x, z