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: ['135', 'u', '3435', '2985', '9811', 'y', '4309', '9757', '905', 'd', 'g', 'q', '1457', 'l', 'o', 'u', '4517', '2333', '3327', '577', 'a', '4041', '8101', '6211', 'f', 'j', '1721', '7217', 'q', '7443', '8477', '3117', '7779', '9339', '8615', 'm', 'c', 'f', 'c', '8979', '7895', 'k', 'w', '1619']

SOLUTION: a, c, d, f, g, j, k, l, m, o, q, u, w, y

PROBLEM: ['7561', 'r', '3419', 'k', 's', '5997', 'u', '6635', '7003', '8491', 'i', '9835', 'c', '8827', 'h', 'a', 'j', '7675', '1995', '1223']

SOLUTION: a, c, h, i, j, k, r, s, u

PROBLEM: ['365', '9829', '2795', 'j', 'm', 'o', 'q', 'w', 'v', '5815', '6477', 'h', 't', '7417', '3063', '6933', '2201', 'u', '2825', 'j', '4083', 'q', '6913', 'z', 'c', '3133', '7425', 'c', 'h', 'e', '3555', '1233', '5313', 'k']

SOLUTION:
c, e, h, j, k, m, o, q, t, u, v, w, z