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.

['4925', 'i', 'q', 'k', '7615', 'r', '7217', 'o', '8097', '9151']
i, k, o, q, r

['z', '5601', '5675', 'w', 's', 'z', '9213', '9563', '1699', 'p', 'g', 'm', 'c', '9279', '4481', 'p', 'n', '2389', 'c', '503', '1901', '8827', '1701', '1607', '5633', 'a', 'z', 'g', '3175', 's', 'l', 'l', '6811', '1821', '693', '8277', 'q', '8623', 'o']
a, c, g, l, m, n, o, p, q, s, w, z

['v', 'b', '8119', '9563', '8319', '3505', 'r', 'g', '2883', 'h', 'n', 'h', '2151', '5581', 'o', 'o', 'n', 's', '7413', '3429', 'd', '9577', 'e', 'p', '4011', '5075', 'b', 'r', '4619', '5717', 'i', '8625', 'h', 'd', 'o', '1883', '3487']

b, d, e, g, h, i, n, o, p, r, s, v