#include <stdio.h>

#define true 1
#define false 0
#define size 8190

char flags[size+1];

main()
{
    int i,prime,k,count,iter;
    printf("10 iterations\n");
    for (iter = 1; iter <= 10; iter++)
    {   count = 0;
        for (i = 0; i <= size; i++) flags[i] = true;
        for (i = 0; i <= size; i++)
        {   if (flags[i])
            {   prime = i + i + 3;
                for (k = i+prime; k <= size; k += prime)
                    flags[k] = false;
                count++;
            }
        }
    }
    printf("\n%d primes.\n", count);
}