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 is below.
Q: ['8129', 'a', '4245', 'y', 'm', 'a']
A: a, m, y
Rationale: Here, the unique alphabets in the list are 'a', 'y', and 'm', hence their sorted order is 'a, m, y'.
Q: ['4577', '8825', '1577', 'd', '7963', 'p', '6147', 'v', '8619', 'u', '3193', '8783', '8505', '5591', 'f', 'n', '7881', '8025', '8879', 'h', '3175', 'u', 'q', '253', 'a', 'j', '7785', 'j', 'q', '2887', 'b', '1319', 'c', '1961', 'g', 'i']
A:
a, b, c, d, f, g, h, i, j, n, p, q, u, v