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: ['A', 'A', '6731', '2073', '2497', 'D', 't', '6995', 'E', '31']

1, 1, 6731, 2073, 2497, 4, 20, 6995, 5, 31