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: ['421', '6001', 'N', 'E', '2415', '5541', '7131']

421, 6001, 14, 5, 2415, 5541, 7131