Two test cases not passing

#1

Please tell me where am I wrong. I am not able to pass 2 test cases.

#2

You need to store more prime numbers. Calculate prime number using sieve.

#3

https://ide.codingblocks.com/s/308743 This is the new updated link, plz check, still not getting 2 test cases correct, I passed one other test case but failed one I passed befire

#4

You have to print stack a1 at the end of loop