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: ['2459', '3709', 'f', '8673', '9313', 'm', 'd', 'g', 'c', 'g', 'u', 'f', 'p', 'i', '8771', '3613', '9669', '6221', '1211', '8331', '2295', 'b', 'f', 'm', '1377', '9831', '1751', 'k', '4831', 'm', '2747', '3435', '4543', 'c', '1729', 'e', '7093', '397', 'm', '383', '2019']

SOLUTION: b, c, d, e, f, g, i, k, m, p, u

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: ['1913', 'h', '3599', 'l', '4387', 'v', '5785', 'j', '6469', 'r', 't', '4417', 'w', '6129', 's', 'e', '4511', 'k', 'm', '6623', '8511', '1919', 'r', 's', 'z', 'c', '675', '5455', '1103', '6423', '947', '5579', '3239', 'i', '9641', '5649', '5895', 'h', '3865', '5921', 'i', '3471', 'w', 'i', 'g']

SOLUTION:
c, e, g, h, i, j, k, l, m, r, s, t, v, w, z