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: ['t', 'U', '4407', '8601', 'd', 'D', '1209', '7387', 'A', '6899', 'k', '653', '1929', '4271', 'a', '997', 'Z', 'S', 'A', 'Z', 'o', 'E', 'p', 'Q', 'r', 'J']

20, 21, 4407, 8601, 4, 4, 1209, 7387, 1, 6899, 11, 653, 1929, 4271, 1, 997, 26, 19, 1, 26, 15, 5, 16, 17, 18, 10