ISSUE OF TEST CASES

Kindly educate me as to how do these test cases work, so that I don’t have to, again and again, post doubts. The code functions perfectly but the test cases fail somehow.

there are just corner test cases and you ll always face them you just have to cover all the cases that you can
here in your code u need to use long looking at the constraints
use Long.parseLong in line 60 and 61
long val1int = Long.parseLong(val1);