//-----------------------------------------------------------------------
//	File:		prob.cc
//	Description:	Assemble fragmented message
//	Author:		Chau-Wen Tseng (tseng@cs.umd.edu)
//-----------------------------------------------------------------------

#include <stdlib.h>
#include <iostream.h>
#include <assert.h>

// Uncomment the following lines if using APCS classes
// #include "apvector.h"
// #include "apmatrix.h"
// #include "apstack.h"
// #include "apqueue.h"

#include "apstring.cpp"

//-----------------------------------------------------------------------
//  main
//-----------------------------------------------------------------------

int main()
{
	const int FRAGSIZE = 12;
	const int MAXFRAG = 100;
	apstring frag[MAXFRAG], result;
	int numFrag, i;

	// read in all fragments

	cin >> numFrag;
	for (i = 0; i < numFrag; i++) {
		cin >> frag[i];
		if (frag[i].length() != FRAGSIZE) {
			cout << "ERROR, illegal fragment size " << frag[i] << endl;
		}
	}

	//////////////////// BEGIN your solution /////////////////////////////

	result = frag[0];

	//////////////////// END your solution /////////////////////////////

	cout << result << endl;

	return 0;
}