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: ['449', 'a', 'u', '4849', 'U', 'e', '2529', 'W', 'h', '6625', 'G', '2255', '2903']

449, 1, 21, 4849, 21, 5, 2529, 23, 8, 6625, 7, 2255, 2903