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: ['6867', 'N', 'O', '9579', '891', '9069', 'x', 'R', 'g', '7455', '1749', '5209', '8039', '9477', '4765', 'S', 'm', '3893', 'P', '157', 'J', 'Y', 'Z', '5917', 'D', '9741', '1573', 'R']

6867, 14, 15, 9579, 891, 9069, 24, 18, 7, 7455, 1749, 5209, 8039, 9477, 4765, 19, 13, 3893, 16, 157, 10, 25, 26, 5917, 4, 9741, 1573, 18