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', 'f', '3409', 'N', 'U', 'Y', 'c', '1007', 'Z', '3635', '6317', 't', '5555', '2801', 'i', '2113', '5491', 'M', '1371', '4577', 'I', 's', '5713', 'j', '8221', 'y', 'I', '1845', '767', '6203', '7193', 'F', '1135', '8617', '8809', '4799', '459', '9529', 'I']

9, 6, 3409, 14, 21, 25, 3, 1007, 26, 3635, 6317, 20, 5555, 2801, 9, 2113, 5491, 13, 1371, 4577, 9, 19, 5713, 10, 8221, 25, 9, 1845, 767, 6203, 7193, 6, 1135, 8617, 8809, 4799, 459, 9529, 9