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: ['6711', 'o', 'M', 'H', 'O', '3329', 'L', '3051', 'N', '423', '5479', 'n', 'g', '4301']

6711, 15, 13, 8, 15, 3329, 12, 3051, 14, 423, 5479, 14, 7, 4301