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 concatenate all elements of A from the ith element to the jth element, and print 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.
Input: 7, 21, ['9435', '3105', 's', 'y', '5587', '3687', 'D', 'R', 'L', '9693', 'z', '3041', 'g', '903', 'J', '3579', '9843', 'O', '9709', '5965', 'J', '561', '2173', 'u', '399', 'f']

DRL9693z3041g903J35799843O97095965J