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: ['A', '6985', '1815', 'z', 'n', '3643', 'w', 'f', '2213', '7203', 'R', 'O', 'u', 'o', '3651', '2005']

1, 6985, 1815, 26, 14, 3643, 23, 6, 2213, 7203, 18, 15, 21, 15, 3651, 2005