#include <iostream>
#include <set>
#include <vector>

using namespace std ;

int main()
{
	vector<int> v1 ;
	set<int> set1 ;

	v1.push_back( 4 ) ; v1.push_back( 2 ) ; v1.push_back( 4 ) ;
	v1.push_back( 1 ) ; v1.push_back( 2 ) ;
	for( int x1 : v1 )
	 cout << x1 << " " ;
	cout << endl ;

    //Remove duplicates in v1 . Keep the order the same.
    //Do not use any other data structures like vector
    // other than v1 and set1 defined above.
    //Do not use nested loops. Only 1 loop




	for( int x1 : v1 )
	 cout << x1 << " " ;
	cout << endl ;


	return 0;
}