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: ['c', 'l', '9161', '7709', '3539', '1691', 'f', 'i', '1463', '365', '3995', 'o', '1309', '7509', '3711', '3891', 'r', '4583', '667', 'n', '7353', 'j', '9479', 'd', '3459', '4027', '5961', 'c', 'v', '7753', 'p', 'e', 'd', 'c', 'e', '7101', '2303', '6265', 't', 's', '7521', 'h', '5477', '9083', '3331']
A:
c, d, e, f, h, i, j, l, n, o, p, r, s, t, v