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, 17, ['U', '7559', 'l', 'H', 'I', 'V', '3127', 'R', 'v', 'R', 'U', '5627', 'E', 'F', 'f', 'U', 'k', '7781']

3127RvRU5627EFfUk