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: ['Y', '9961', 'Q', 'H', '1265', 'V', '1929', 'e', '2419', 'Z', 'u', '4861', '1123', '4655', 'R', 'I']

25, 9961, 17, 8, 1265, 22, 1929, 5, 2419, 26, 21, 4861, 1123, 4655, 18, 9