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: 12, 21, ['8659', '943', '4713', '4417', '3571', '4913', '1163', '5307', '2927', '8647', 'x', 'g', '2507', 'L', '7183', '3785', 't', '2763', 'W', 'M', '6405']

g2507L71833785t2763WM6405