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: ['8051', 'h', 'g', 's', 't', 'p', 'w', 'x', 's', '8521', 'm', '9719', 'j', 'n', 'i']

A: g, h, i, j, m, n, p, s, t, w, x
****
Q: ['t', 'h', '6141', 'g', 'f', 'z', 'n', 'b', 'k', '9059', 'y', 'p', '4289', '2683', 'a', '3267', 'w', 'p', 't', '3623', '7759', 'a', 'o', 'm', '9815', 'q', 'u', '8051', '6871']

A: a, b, f, g, h, k, m, n, o, p, q, t, u, w, y, z
****
Q: ['2507', 'w', 'r', 'w', 'h', '8837', 's', '8435', '9105', '1565', 'a', 'm', 'g', 'i', '8047']

A:
a, g, h, i, m, r, s, w
****