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: ['M', '7471', '2917', '9049', '4223', 'o', '6639', '7953', '4529', '3297', '8809', 'I', '1289', 'O', 'm', 'f', '9291', '6475']

13, 7471, 2917, 9049, 4223, 15, 6639, 7953, 4529, 3297, 8809, 9, 1289, 15, 13, 6, 9291, 6475