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: ['O', 'j', 'n', 'r', 'H', 'u', 'r', '7833', '1849', 'D', 't', '4147', 'D', '1035', '5891', '2817', 'z', 'W', '5927', '99', 'f', '3691', 'x', 'C', 'j']

15, 10, 14, 18, 8, 21, 18, 7833, 1849, 4, 20, 4147, 4, 1035, 5891, 2817, 26, 23, 5927, 99, 6, 3691, 24, 3, 10