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: ['1969', '3879', '6383', '417', '2637', '8129', 'n', 'i', 'D', '7373', 'K']

1969, 3879, 6383, 417, 2637, 8129, 14, 9, 4, 7373, 11