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.

['57', 'j', 'n', '877', 'u', 'w', 'j', 'f', '8977', 'h', '469', '9417']
f, h, j, n, u, w

['o', '9599']
o

['791', 'f', 'k', 'f', '6205', '3523', 'i', '8899', '4719', 'y', '9497', '9671', '2555', '4975', '9885', 'z', '8807', '9827', 'c', 'l', '4275', 'c', 'd', '1083', '3331', '5633', 'i', 'u', '4817', 'c', 's', '9201', '7737', 'j', 'h', 's', 'c', 'o', '1995', '7069', 'm']

c, d, f, h, i, j, k, l, m, o, s, u, y, z