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: ['8261', 'h', '9201', 'd', 'e', '8081', '6789', 'w', 'h', '1991', '1661', '1461', '8455', 'n', '1379', 'x', '6919', '9417', 'n', '4271', 'j', '247', '2859', 'i', '9053', 'f', '7091', '2703', 'v', 'd', 'a', 'l', 'c', '387', 'p', '2717', 'g', 'r', '8235', '2865', '6491', 'a', 'x', '7637']
Solution:
a, c, d, e, f, g, h, i, j, l, n, p, r, v, w, x