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: ['D', '7407', 'f', 'X', 'j', 'N', 'B', '6413', '6805', '3719', '6159', '311', '129', 'S', 'q', 'Z']

4, 7407, 6, 24, 10, 14, 2, 6413, 6805, 3719, 6159, 311, 129, 19, 17, 26