TASK DEFINITION: In this task, you are given an input list A. You need to convert all the alphabets in the list with a number representing their position in the English alphabet. E.g., replace A by 1, B by 2, a by 1, b by 2, and so on.
PROBLEM: ['6881', 'F', '4759', '5797', '4879', '5761', '9913', '8509', 'c', 'X', 'U']

SOLUTION: 6881, 6, 4759, 5797, 4879, 5761, 9913, 8509, 3, 24, 21

PROBLEM: ['j', '5075', 'R', 'I', 'y', '7405', '5539', '6463', '8961', '1803', '8897', '1929', 'E', 'N', '9433', 'C']

SOLUTION: 10, 5075, 18, 9, 25, 7405, 5539, 6463, 8961, 1803, 8897, 1929, 5, 14, 9433, 3

PROBLEM: ['4487', 'j', '7771', 'N', '287', 'w', 'l', 's', 'c', '3285', '3581', '9605', '9407', 'E', 'd', '4565', '141', '4599', '6513', '1107', '9487', '5509', '441', 'i', 's', '1329']

SOLUTION:
4487, 10, 7771, 14, 287, 23, 12, 19, 3, 3285, 3581, 9605, 9407, 5, 4, 4565, 141, 4599, 6513, 1107, 9487, 5509, 441, 9, 19, 1329