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.
Input: ['H', 'U', 'G', '9721', 'y', '5803', '2061', 'a', 'm', 'N', '1859', 'U', 't', '4649', '4885', '303', 'P', '7465', '3535', 'w', '1813', '6037', 's', '4253', 'O', 'j', 'I', 'w', '6625', '5357', 'R', '5901', 'L', '6347', '819', '1075', '3923', 'X', '7573']

8, 21, 7, 9721, 25, 5803, 2061, 1, 13, 14, 1859, 21, 20, 4649, 4885, 303, 16, 7465, 3535, 23, 1813, 6037, 19, 4253, 15, 10, 9, 23, 6625, 5357, 18, 5901, 12, 6347, 819, 1075, 3923, 24, 7573