#include <iostream>
#include <vector>

using namespace std;

void Add_Doubles(vector<int> & A){
	for (int i=0; i< A.size(); i++)
		A.push_back(2*A[i]);
}

void print (const vector<int> & A){
	for (int i=0; i<A.size(); i++)
		cout << A[i] <<" ";
	cout << endl;
}

int main(){
	vector<int> A;
	A.push_back(1);
	A.push_back(2);
	Add_Doubles(A);
	print(A);
	Add_Doubles(A);
        print(A);
	return 0;
}