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', '2821', 'K', 'T', '1667', '1449', '5659', 'P', 'A', '2115', 'P', 'm', '1287', '7809', 'F', '6151', 'i', 'C', 'N', 'Y', '5123', '6511', 'd', '2619', 'Y', '3391']

18, 2821, 11, 20, 1667, 1449, 5659, 16, 1, 2115, 16, 13, 1287, 7809, 6, 6151, 9, 3, 14, 25, 5123, 6511, 4, 2619, 25, 3391