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: 11, 19, ['F', 's', 'D', 'B', '2137', 'r', '7797', '3379', 'I', 'T', '7857', 'W', '6679', 'l', 'j', '5463', 'j', '759', 'n']

7857W6679lj5463j759n