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.

Q: ['5163', 'n', 'j', '67', '3801', 'n', '7113', 'z', '579', '6885', '8921', 'v', '5481', '5507', 'k', '8403', 'c', '837', 'u', '6341', 'd', 'i', '497']

A: c, d, i, j, k, n, u, v, z
****
Q: ['1749', 'i', 'w', 'j', '3171', '1999', '1037', '4937', '7013', '3593', '287', 'o', 'i', 'j']

A: i, j, o, w
****
Q: ['n', 's', 'g', 'p', 'i', 's', 'f', '5513', '8735', '7375', 'd', '8273', 'z', '17', '6441', '1261', '9291', 'p', 'e', 'a', '5883', '1801', 'h', '1789', '1719', 'q', 'b', '8651']

A:
a, b, d, e, f, g, h, i, n, p, q, s, z
****