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: ['3191', 'T', '1249', '999', 'R', 'A', 'M', '1437', '1139', '7007', '3627', 'O', '5509', '5239', 'R', 'n', 'I', 'm', 'X', 'H', '5475', '7081']

3191, 20, 1249, 999, 18, 1, 13, 1437, 1139, 7007, 3627, 15, 5509, 5239, 18, 14, 9, 13, 24, 8, 5475, 7081