#!/usr/bin/env cscript
#include <stdio.h>
#include <string.h>
#define ALPHABET "ABCDEFGHIJKLMNOPQRSTUVWXYZ"

int
main(int argc, const char *argv[]) {
	char column_string[3 + 1], column_string_next[3 + 1], *needle_column_string;

	strcpy(column_string, "A");

	for (int i = 1; i <= 82; i++) {
		puts(column_string);

		for (needle_column_string = &column_string[strlen(column_string) - 1];
		     needle_column_string >= column_string; needle_column_string--) {
			if (*needle_column_string != 'Z') {
				*needle_column_string += 1;
				continue;
			}

			strcpy(column_string_next, column_string);

			column_string = column_string_next;
		}
	}

	return 0;
}