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: ['6741', 'S', '2637', 'E', 'L', 'u', 'R', '1137', 'n', '7123', 't', 'l', 'F', '2535', 'r', 'J', '4243', '3555', 'S', '7313', 'H', '4859', 'I', '3637', '8069', '6233', 'e', 'n', 'h', '6409', '2981', '5695', 'c', 'G', 'O', 'B', 'Z']

6741, 19, 2637, 5, 12, 21, 18, 1137, 14, 7123, 20, 12, 6, 2535, 18, 10, 4243, 3555, 19, 7313, 8, 4859, 9, 3637, 8069, 6233, 5, 14, 8, 6409, 2981, 5695, 3, 7, 15, 2, 26