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: ['4749', '4169', 'S', 'u', '2367', 't', '9783', 'N', '9567', 'p', '4149', '7937']

4749, 4169, 19, 21, 2367, 20, 9783, 14, 9567, 16, 4149, 7937