import os


def dir_walk(main_dir="."):
    file_set = set()

    for root, dir, files in os.walk(main_dir):
        for file_name in files:
            rel_dir = os.path.relpath(root, main_dir)
            rel_file = os.path.join(rel_dir, file_name)
            file_set.add(rel_file)
    print(f"{len(file_set)} files found:")
    print(file_set)
    return file_set


if __name__ == "__main__":
    dir_walk()