Definition: In this task, you are given inputs i, j, and A, where i and j are integers and A is a list. You need to find all elements of A from the ith element to the jth element, reverse the order in which they occur, and then concatenate them to output the resultant 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 concatenate the elements and then reverse the string.
Input: 2, 20, ['N', 'N', 'n', 'f', 'E', '7217', 'B', '7957', '8477', 'A', '6293', '7123', 'P', '4601', '3237', '9561', 'S', 'Q', 'I', 'p']

pIQS956132374601P71236293A84777957B7217EfnN