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: ['U', '1531', 't', '6929', 'P', '9619', 'G', 'g', '8511']

SOLUTION: 21, 1531, 20, 6929, 16, 9619, 7, 7, 8511

PROBLEM: ['R', '4841', '221', 'p', 'K', '8845', '1765', '7773', 'D', '9859', '8781', 'n', 'J', 's', 'N', '221', '6879', '1257', 'a', 'O', '393', '7189']

SOLUTION: 18, 4841, 221, 16, 11, 8845, 1765, 7773, 4, 9859, 8781, 14, 10, 19, 14, 221, 6879, 1257, 1, 15, 393, 7189

PROBLEM: ['r', 'b', 'O', '5523', '4843', 'F', '6193', 'O', 'Y', 'U', 'j', '5585', 'W', 't', 'h', '4863', '4667', 'g', '4821', '8391', 'r', 's', 'M', '511', 'h', '3373', '1015', '7343', 'n', '2031', 'Y', 'L', 'B', '8041', '2287']

SOLUTION:
18, 2, 15, 5523, 4843, 6, 6193, 15, 25, 21, 10, 5585, 23, 20, 8, 4863, 4667, 7, 4821, 8391, 18, 19, 13, 511, 8, 3373, 1015, 7343, 14, 2031, 25, 12, 2, 8041, 2287