Please either format your code or link to your submission 
Can you give a testcase that shows the issue you’re having?
Edit:
Your code will throw an Exception (which is silently smothered) if the input does not contain a 7.
Edit2:
Given the testcase
1
13
1 2 3 4 5 6 7 6 5 4 3 2 1
(which should output yes), subString1 and compare are not the same string - can you see why?