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: ['r', 'q', '3519', 'a', 'l', 'O', 'z', '9437', 'c', 'l', '1027', '9131', 'a', '9961', '1435', '1839', 'l', '4419', '7745', 'X', '9677', '2995', '2099', 'V', '1625', 'b', '1469', '2385']

18, 17, 3519, 1, 12, 15, 26, 9437, 3, 12, 1027, 9131, 1, 9961, 1435, 1839, 12, 4419, 7745, 24, 9677, 2995, 2099, 22, 1625, 2, 1469, 2385