instruction:
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.
question:
['1223', 'h', 'a', 'o', 'v', '2535', 'g', '6267', 'w', '9625', '7961', '9577', '7611', '5655', 'p', 'j', 's', '2141', '4101', 'l', '4367', '9383', 'n', '5965', '9097', '7571', 'p', 'u', 'x']
answer:
a, g, h, j, l, n, o, p, s, u, v, w, x


question:
['t', 'c', 'r', '4459', 'o', '1407', 'x', '1515', '331', 'm', '1535', 'p', 'u', 'g', '2513', 'o', '7827', '8149', 'd', 'z', 'q', '5655', 'x', '9997', '2809', 'g', 'h', '6309', 'a', 'j', '9773', '2115', 't', '9113', 'q', 'o', '427', 's', '3815', '5423', 's', 'n', 'i', 'o', '3643']
answer:
a, c, d, g, h, i, j, m, n, o, p, q, r, s, t, u, x, z


question:
['m', '3671', 'd', 'k', 'd', '1047', 'z', 'g', 'j', '6455', '7241', '545', 'p', 'j', '2827', '7995', 'z', 'w', 't', 'j', 's', 'm', '8689', '9333']
answer:

d, g, j, k, m, p, s, t, w, z