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

#define DIVTHREE 1
#define DIVFIVE (1<<2)
#define DIVBOTH (DIVTHREE | DIVFIVE)
#define DIVNEITHER 0

int main(int argc, char *argv[])
{
        long int start, end, current;
        char *endp;

        if (argc < 2) {
                fprintf(stderr, "usage: %s <start> <end>\n", argv[0]);
                exit(EXIT_FAILURE);
        }

        start = strtol(argv[1], &endp, 10);
        if (endp == argv[1]) {
                fprintf(stderr, "invalid start number.\n");
                exit(EXIT_FAILURE);
        }

        end = strtol(argv[2], &endp, 10);
        if (endp == argv[2]) {
                fprintf(stderr, "invalid end number.\n");
                exit(EXIT_FAILURE);
        }

        if (end < start) {
                fprintf(stderr, "end number should not be less than start.\n");
                exit(EXIT_FAILURE);
        }

        for (current = start; current <= end; current++) {
                switch ( (current % 3 ? 0 : DIVTHREE) |
                         (current % 5 ? 0 : DIVFIVE) ) {
                        case DIVTHREE:
                                printf("fizz\n");
                                break;
                        case DIVFIVE:
                                printf("buzz\n");
                                break;
                        case DIVBOTH:
                                printf("fizzbuzz\n");
                                break;
                        case DIVNEITHER:
                                printf("%ld\n", current);
                                break;
                        default:
                                fflush(stdout);
                                fprintf(stderr, "your CPU is broken.\n");
                                exit(EXIT_FAILURE);
                }
        }

        exit(EXIT_SUCCESS);
}