TASK DEFINITION: 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.
PROBLEM: ['d', '5285', 'z', 't', 'i', '719', 'z', 'b', '3603', '4781', 'o', 'g', 'j', 'd', 'r', 'a', 'x', '5829', '4907', '7395', '993', '2109', '1745', '415', '7525', '1029', '7791', '5321', 'h', '6391', 'g', '4613', '9191', 'o', '7365', '1811', '9695', 'w']

SOLUTION: a, b, d, g, h, i, j, o, r, t, w, x, z

PROBLEM: ['l', 'o', 's', '7411', '7847', '2557', '1977', '2863', '2325', '4177', '4183', '4241', '1005', '1137', '1371', 'v', 'p', 'a', '2453', 'l', '6315', 'l', '6463', 'n', '7645', '9669', '5411', '1631', '5995', 'z', '227']

SOLUTION: a, l, n, o, p, s, v, z

PROBLEM: ['8647', '6135', '7165', '815', 'e', 'i', 't', 'c', 'd', '549', 'f', '617', 'h', '1415', '1235', '6501', '8907', '7455', '7695', '8973', 'p', 'd', 's', '4277', 'x', '7867', 'p', 'o', '2353']

SOLUTION:
c, d, e, f, h, i, o, p, s, t, x