Shows correct answer for custom test case but wrong upon final submission

#1


unable to point out the error

#2

You are getting wrong answer because of integer overflow. Please use long long int.

#3

https://ide.codingblocks.com/s/235440 shows TLE for 1 test case

#4

Yeah the Time limit is way too strict, so had to use scanf for taking input.
Here is the code https://ide.codingblocks.com/s/238815