#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);
}