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: ['b', 'S', 'T', 'G', 'b', '147', 'n', 'w', 'T', 'm', '6377', '5455', '7777', 'v', '7383', 'o', 'O']

2, 19, 20, 7, 2, 147, 14, 23, 20, 13, 6377, 5455, 7777, 22, 7383, 15, 15