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.

[EX Q]: ['u', 'o', 'b', 'b', '5873', 'w', 'v', '4171', '7957', '3501', '2563', 'l', 'q']
[EX A]: b, l, o, q, u, v, w

[EX Q]: ['2633', 'd', 'r', '8083', 'f', 'd', '5121', '8651', 'o', 'b', '811', '7551', 'x', 'p', 'm', 'v', 'm', '7833', '1959', 'y', 'p', '779', '1889']
[EX A]: b, d, f, m, o, p, r, v, x, y

[EX Q]: ['4087', '4831', 'k', 'm', '7693', 'y', 'c', 'x', '3419', '6727', '3501', '4311', '2203', 'n', 'i', 'j', '3201', '4291', 'r', 'l', '5375', '8179', 'm', 'n', '8685', 'q', '2537', '333', 'p', '7939', '6605', 'i', 'i', 'p']
[EX A]:
c, i, j, k, l, m, n, p, q, r, x, y