TASK 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.
PROBLEM: ['6521', 'f', 'm', '1051', 'w', 'C', 'H', 'X', '7715', '5243', '3365', 'l', 'X', 'J', 'y', 'U', '4367', 'v', '8399', '1731', 'z']

SOLUTION: 6521, 6, 13, 1051, 23, 3, 8, 24, 7715, 5243, 3365, 12, 24, 10, 25, 21, 4367, 22, 8399, 1731, 26

PROBLEM: ['7511', 'c', '5999', 'j', '2265', 'E', '9905', '1861', '8743', '873']

SOLUTION: 7511, 3, 5999, 10, 2265, 5, 9905, 1861, 8743, 873

PROBLEM: ['5447', 'v', 'S', 'F', '6039', 'U', '2635', '3493', 't', 'Z', '675', 'p', 'q', '5367', 'e', '1749', '1323', '8083', '6475']

SOLUTION:
5447, 22, 19, 6, 6039, 21, 2635, 3493, 20, 26, 675, 16, 17, 5367, 5, 1749, 1323, 8083, 6475