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: ['F', '399', 'l', 'V', '6595', 'P', '1873', 'H', 'T', '5063', 'y', '5921', '5769', 'G', 'o', '3839', 'o', 'm', '3877', 'V', 'x', 'V', '5673', '7877', '9021', 'K']

6, 399, 12, 22, 6595, 16, 1873, 8, 20, 5063, 25, 5921, 5769, 7, 15, 3839, 15, 13, 3877, 22, 24, 22, 5673, 7877, 9021, 11