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: 11, 15, ['Y', 'L', 'I', 'u', 'z', '4077', 'K', '4679', 'l', '9269', '4071', '1789', 'b', '2139', 'b', '111', '6715', 'H', '3981']

b2139b17894071