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: ['2459', '3709', 'f', '8673', '9313', 'm', 'd', 'g', 'c', 'g', 'u', 'f', 'p', 'i', '8771', '3613', '9669', '6221', '1211', '8331', '2295', 'b', 'f', 'm', '1377', '9831', '1751', 'k', '4831', 'm', '2747', '3435', '4543', 'c', '1729', 'e', '7093', '397', 'm', '383', '2019']

A: b, c, d, e, f, g, i, k, m, p, u
****
Q: ['w', '491', 'x', 'u', 'z', 'q', '5411', '7629', '8261', '8629', '1441', '5139', 's', 'm', '6463', 'u', 'z']

A: m, q, s, u, w, x, z
****
Q: ['8115', '6339', 'k', '5817', '8603', 'b', '3935', '5027', '2543', 'r', 'o', '3977', 'k', '5671', 'z', 't', '2095', '3509', '5543', 't', 's', 'q', 'o', 'z', '6071']

A:
b, k, o, q, r, s, t, z
****