TASK DEFINITION: In this task, you are given inputs 'i', 'j', and A, where 'i' and 'j' are integers and A is a list. A list is shown by two brackets and comma-separated numbers and characters inside, like ['1', '12', 'l']. You need to concatenate all elements of A from the ith element to the jth element, and then reverse the resulting string. 'i' and 'j' will be non-negative, and will always have a value less than the length of A. 'i' will always be less than 'j'. Perform the operations in order, i.e., do not reverse first and then concatenate.
PROBLEM: 10, 18, ['S', 'S', '6525', '3017', '9729', '5747', '4409', '9501', '4083', 'f', 'X', 'B', 'u', '5967', '9949', '7227', '6993', '8105', 'n', 'C', '2131', '3105', 'd', 'E']

SOLUTION: 50183996722794997695uBXf

PROBLEM: 3, 5, ['2849', 'J', 'L', '2347', '7219', 'a', 'Q', 'U', '6865', 'O']

SOLUTION: 91277432L

PROBLEM: 4, 14, ['6995', 'j', '7159', 'k', '3555', 'Q', 'G', 'a', '3649', 'm', '2587', '6701', 'l', 'K']

SOLUTION:
Kl10767852m9463aGQ5553k