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]: ['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]: ['2995', '8179', '8131', '5655', 'j', 'q', 'l', '3193', '1823', 'y', 'n', '7645', 's', '5665', 'r']
[A]: j, l, n, q, r, s, y


[Q]: ['6467', '3783', '7457', '3897', '1381', 'c', '8057', '8859', '4119', '9835', '659', 'n', '3533', '2497', 'h', 'p', 'q', '9261', '9573', '8247', '2061', 'o', '5385']
[A]:
c, h, n, o, p, q