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: ['4819', 'K', '7617', '4313', '6789', 'L', 'O', 't', '9925', '2441', '7915', '5687']

4819, 11, 7617, 4313, 6789, 12, 15, 20, 9925, 2441, 7915, 5687