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', 'L', '7455', 'F', '8023', 'Y', '5859']

13, 12, 7455, 6, 8023, 25, 5859