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: ['I', '1991', 'w', 'k', '4869', 'T', 'D', '6145', 'D', '6405', 'Z', 'c', 'z', 'w', 'n', '3783', '5171', 'x', 'F', 'P', 'A', 'r', 'K', '1167', '7049', '3099', 'T', '7065', '1221', 'O', '7479', 'd', 'L']

9, 1991, 23, 11, 4869, 20, 4, 6145, 4, 6405, 26, 3, 26, 23, 14, 3783, 5171, 24, 6, 16, 1, 18, 11, 1167, 7049, 3099, 20, 7065, 1221, 15, 7479, 4, 12