#include <iostream>
#include <list>
using namespace std;

int main() {
	std::list<int> tempList;
	for (int i = 0; i < 10; ++i)
		tempList.push_back(i);
		
	for (auto it = tempList.begin(); it != tempList.end(); ++it) 
		cout << *it << endl;
	for (auto it = tempList.begin(); it != tempList.end(); ++it)
		cout << *it * 2 << endl;
	return 0;
}