#include <iostream>
#include <string>
#include <vector>

using namespace std;

class BaseObject {
private:
	string name;
	BaseObject * root;

public:
	vector<BaseObject*> childs;
	vector<BaseObject*>::iterator it_child;

	BaseObject(BaseObject * root = nullptr, string name = "");
	void set_name(string& name);
	string get_name();
	void set_root(BaseObject * new_root = nullptr);
	BaseObject * get_root();
	void add_child(BaseObject * child);

	void show_object_tree();
	void show_object_next(BaseObject * root, int level);
};

void BaseObject::set_name(string& new_name) {
	this->name = new_name;
}

string BaseObject::get_name() {
	return this->name;
}

void BaseObject::set_root(BaseObject *new_root) {
	if (new_root) {
		root = new_root;
		root->add_child(this);
	}
}

BaseObject::BaseObject(BaseObject *root, string name) {
	set_name(name);

	set_root(root);

}

void BaseObject::add_child(BaseObject *child) {
	childs.push_back(child);
}

void BaseObject::show_object_tree() {
	int level = 0;
	show_object_next(get_root(), level);
}

void BaseObject::show_object_next(BaseObject *root, int level) {
	cout << root->get_name() << "\n";
	if (root->childs.empty()) {
		return;
	}
	root->it_child = root->childs.begin();
	while (root->it_child != root->childs.end()) {
		show_object_next(*(root->it_child), level++);
		root->it_child++;
	}
}


class Application : public BaseObject {
public:
	void build_tree_objects();
	int exec_app();
	void show_object_tree();

private:
	void show_object_next(BaseObject * root, int level);
};

void Application::build_tree_objects() {
	string main_root_name, root_name, child_name;
	cin >> main_root_name;
	this->set_root(new BaseObject(nullptr, main_root_name));

}

int main() {
	Application app;
	app.build_tree_objects();
	return app.exec_app();
}