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: ['2157', '9919', 'F', '6687', '3917', '8421', '5561', 'C', 'V', 'X', 'K', 'm', 'r', '8197', '6543', '9011', '1083', 'r', 'n', 'y', 'K', 'X', '5929', 'F', '3949', 'b', '2125']

2157, 9919, 6, 6687, 3917, 8421, 5561, 3, 22, 24, 11, 13, 18, 8197, 6543, 9011, 1083, 18, 14, 25, 11, 24, 5929, 6, 3949, 2, 2125