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: 4, 21, ['j', 'k', 'W', '1625', 'Y', '7815', 'q', '415', '3947', '4545', 'K', '3779', '7361', '2469', '3397', 'Y', '4909', 'D', 'Y', '6171', 'T', '7443']

T6171YD4909Y3397246973613779K45453947415q7815Y1625