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: ['o', 'T', '6621', '8523', '7535', 'U', '3333', 'J', '1393', '8607', 'y', '7811', 'a', '4771', '5747', 'Q', '215', 'I', '1607', 'f', 'P', '7275', 'V', 'B', 'm', '4371']

15, 20, 6621, 8523, 7535, 21, 3333, 10, 1393, 8607, 25, 7811, 1, 4771, 5747, 17, 215, 9, 1607, 6, 16, 7275, 22, 2, 13, 4371