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: ['6437', '8831', 'Z', '1117', '267', '5247']

6437, 8831, 26, 1117, 267, 5247