#include <stdio.h>

int is_prime(int number);

int main()
{
   int i;

   for (i = 0; i <= 1000; i++)
      if (is_prime(i))
         printf("%d ", i);
   return 0;
}
/***************************************/
int is_prime(int number)
{
   int i;

   if (number == 0 || number == 1)
      return 0;
   if (number % 2 == 0)
      return number == 2;
   if (number % 3 == 0)
      return number == 3;
   if (number % 5 == 0)
      return number == 5;

   for (i = 7; i * i <= number; i += 2)
      if (number % i == 0)
         return 0;
   return 1;
}