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: ['1203', 'l', '1391', '601', '2781', 't', 'V', 'd', 't', 'O', '8437', 'i', 'v', 'c', '2795', '4429', 'r', 'y', 'd', '4639', '8207', '6113', '1537']

1203, 12, 1391, 601, 2781, 20, 22, 4, 20, 15, 8437, 9, 22, 3, 2795, 4429, 18, 25, 4, 4639, 8207, 6113, 1537