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: ['R', '5811', '8603', '8417', 'z', 'F', '3247', 'E', '1411', '6897', 'K', 'V', '7271', '1243', '5747', 'y', '5453']

18, 5811, 8603, 8417, 26, 6, 3247, 5, 1411, 6897, 11, 22, 7271, 1243, 5747, 25, 5453