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: ['9573', '5929', 'I', '1359', 'w', 'u', 'Y', '9927', '7465']

SOLUTION: 9573, 5929, 9, 1359, 23, 21, 25, 9927, 7465

PROBLEM: ['b', 'u', 'r', '3453', '1663', 'b', '651', 'R', 'U', 'U', 'a', 'b', '2769', 'C']

SOLUTION: 2, 21, 18, 3453, 1663, 2, 651, 18, 21, 21, 1, 2, 2769, 3

PROBLEM: ['525', 'e', 'B', '5097', '3073', 'I', '5431', '7393', 'G', 'w', 'J', '4473', '9731', 'J', '8899', 'O', '9911', '699', '4653', '591', 'T', 'k', '4033', 'Q', '3053', 'C', 'l', 'J', 'S', 'b', '2357', '9631', 'M', '2081', '3719', 'r', 'A', '7699', 'M']

SOLUTION:
525, 5, 2, 5097, 3073, 9, 5431, 7393, 7, 23, 10, 4473, 9731, 10, 8899, 15, 9911, 699, 4653, 591, 20, 11, 4033, 17, 3053, 3, 12, 10, 19, 2, 2357, 9631, 13, 2081, 3719, 18, 1, 7699, 13