02.4 What does the function “Check whether a sequence of digits belongs to a number in the number sequence” do?

For an entered sequence of digits, it is checked whether it belongs to the sequence of digits. I.e.

if the digit sequence is a number of the number sequence,output the index and “0”
if the digit sequence is part of a number of the number sequence, output of the index and the place where the number sequence starts
if the number sequence is not included, output “-1”