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

int main() {
	vector <double> s;
	vector <double> l;
	double a,n;
	while(cin>>a)
	{
		s.push_back(a);
	}
	n=s.size()/2;
	for(int i=0;i<n;i++)
	{
		l.push_back(s.at(i));
		l.push_back(s.at(i+n));
	}
	for(int i=0;i<l.size();i++)
	{
		cout<<l.at(i)<<" ";
	}
	return 0;
}