#include <stdio.h> 
#include <math.h>
#define L 100

main()
{
	long int inp; /*input*/
	long int lnp; /*Large Non Prime*/
	long double r; /*Root*/
	long int fr; /*Floor Root*/
	long int cr; /*Ceiling Root*/
	long int a;  /*result of lnp mod fr*/
	long int b;  /*result of lnp mod sr*/
	long int c; /*counter*/
	long int frt; /*fr tester*/
	long int z = 1; /*efficiency tester*/
	long int e = 0; /* even tester */	

	printf("number>");
        scanf("%d", &inp);	
	
	lnp = inp;

	while (e < 1){		/*ferret out all twos*/
		e = lnp%2;
		if ( e == 0) {
			printf("2 is a factor.\n");
			lnp = lnp/2;
			}
		}
	
	r = sqrt(lnp);		/*get starting point*/
	fr = floor(r);

	frt = fr%2;		/*make starting point odd*/
	if (frt == 0) {
		fr = fr -1;
		}

        c = fr + 2;		/*set stop point*/

	while (c > 2){

		a = lnp%fr;
		/* printf("%d mod %d = %d", lnp, fr, a); */

                if ( a == 0) {		/*then it's a factor*/
			if (fr > 1) {		/*display bullshit*/
	                        printf("%d is a factor. (fr) \n", fr);
				}
			cr = lnp/fr;
			if (cr > 1) {
				if (cr < lnp) {
					printf("%d is a factor. (cr) \n", cr);
					}
				}
			if (cr == lnp) {
				printf("%d is prime. \n", cr);
				}
			c = 1;
                        }

		fr = fr - 2;	/*ready for the next step*/
		c = c - 2;	
		z = z + 1;	/*count steps*/

		}
	printf("That took %d steps.\n", z);	
}