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: ['P', '1119', '4913', 'O', 'n', '4389', '483', '2413', '9803', '6815', 'B', 'c', '7499', '629', 'b', '3903', '4643', 'S', 'Z', '6295', 'o', 'R']

16, 1119, 4913, 15, 14, 4389, 483, 2413, 9803, 6815, 2, 3, 7499, 629, 2, 3903, 4643, 19, 26, 6295, 15, 18