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: ['6689', 'F', '9301', '7915', 'p', 'K', 'm', '8509']

6689, 6, 9301, 7915, 16, 11, 13, 8509