After doing the last of the remaining exam training tests, i also made a program that decides if a number is prime or not. Naturally it’s range is limited, to |x|<2^31, though it’s still quite wide in my opinion. The fun thing is, that while testing with numbers over 12 million, for the third try i managed to hit a prime (12 437 519), so i’m proud now. You can also download the prog. Feel free to use it.