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, 20, ['K', '3871', '2401', '39', 'M', 'q', '1203', '2295', '3075', '2827', '6635', '2155', '6799', 'w', 'k', '3811', '8881', '5193', 'f', 'R', '1965', '2885']

1203229530752827663521556799wk381188815193fR