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: 1, 7, ['9403', 'a', '3185', '8587', 'u', 'h', '8743', 'P', '2331', 'r', 'C', 'C', 'B', 'U', '2789', '2571', '2815']

9403a31858587uh8743