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: ['755', '1489', '6945', 'n', 'h', '5783', '9285', 'z', 'l', '4789', 'b', 'l', 'c', '6441', '7319', '6601', 'u', '2713', 'k', 'q', 't', '3563', '8029', '1519', '211', 'h', '2419', '6735', '1725', 'a', 'z', 'v', 'f', 't', 'x', 'u', '7019', '7513', 'l', 'h', 'x', 'p', '6959', '3985']
Solution:
a, b, c, f, h, k, l, n, p, q, t, u, v, x, z