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: ['z', '6555', 'U', 'f', '1639', '1391', '4177', '1671', 'g', 'e', 'N', '1453', 'p', '3349', '6583', '2291', '1689', 'L', 'U', 'e', '4349', 'n', 'v', '5931', '8937', 'X', '7815', 'F', '5409', 'q']

26, 6555, 21, 6, 1639, 1391, 4177, 1671, 7, 5, 14, 1453, 16, 3349, 6583, 2291, 1689, 12, 21, 5, 4349, 14, 22, 5931, 8937, 24, 7815, 6, 5409, 17