title: decoding the runtime error (SIGFPE)
body: <p>This is a problem on spoj.com (<a href="http://www.spoj.com/problems/PRIC/" rel="nofollow">http://www.spoj.com/problems/PRIC/</a>) .We have to check whether numbers of the sequence : ai=( a(i-1)+1234567890 ) mod 2^31  are prime or not, 1st number is 1. 
  My code is given below (Please try to ignore the clumsiness.) based on sieve of eratosthenes .</p>
  
  <p>The PROBLEM : We have to print "prime(1) or not(0)" for sequence upto i=33,333,333 , My code works perfectly fine for i( c3 in the code) values upto 8000 or so and after that (e.g c3>19000 ) it starts giving The SIGFPE error . Now i googled about the error , it has something to do with division/ mod by 0. But why is it that code works for c3 values upto 9000 but not beyond that?</p>