#include <stdio.h>
#include <stdlib.h>
#include <comma.h>

main()
{
	unsigned long a,b,d,f;
	char c,e;
	char s[20];

	a=1;

	c=0;
	d=1;
	e=0;

	printf("      1: ");

	while (a<1000) {
		for (b=3;b<a;b+=2) {
			if (a%b == 0) break;
		}
		if (b == a) { // prime!
			printf("%9ld",a);
			e++;
			if (e == 0) cprintf("%8ld: %10ld\n\r",d,a);
			c++;
			d++;
			if (c < 7) {
				printf(" ");
			} else {
				printf("\n%7ld: ",d);
				c=0;
			}
		}
		a+=2;
	}

	while (!kbhit() && d < 28916) {
		// check a
		f = a>>1;
		for (b=3;b<f;b+=2) {
			if (a%b == 0) break;
		}
		if ((b == f+1) || (b == f)) { // prime!
			printf("%9ld",a);
			e++;
			if (e == 0) cprintf("%8ld: %10ld\n\r",d,a);
			c++;
			d++;
			if (c < 7) {
				printf(" ");
			} else {
				printf("\n%7ld: ",d);
				c=0;
			}
		}
		a+=2;
	}
	return 0;
}