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: 1, 4, ['I', '5919', 'J', '6387']

SOLUTION: 7836J9195I

PROBLEM: 3, 4, ['435', 'K', '8051', '7159']

SOLUTION: 95171508

PROBLEM: 3, 18, ['6561', '3871', 'U', 'x', '3585', '3019', '8405', '9853', 'V', 'M', 'k', '1269', 'm', '5813', '4963', 'V', '4091', '5547', '6369', 'z', '697']

SOLUTION:
74551904V36943185m9621kMV3589504891035853xU