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: ['291', 'W', 'L', 'e', 'N', '4361', '2957', 'T', '3319', '191', 'R', '7203', 'L', '3055', '3425', '5323', 'U', 'N', '445']

291, 23, 12, 5, 14, 4361, 2957, 20, 3319, 191, 18, 7203, 12, 3055, 3425, 5323, 21, 14, 445