BerOilGasDiamondBank has branches in n cities, at that n is an even number. The bank management wants to publish a calendar with the names of all those cities written in two columns: the calendar should consist of exactly n / 2 lines of strictly equal length, each of which contains exactly two names and exactly one separator character between them. The name of every city should be used in the calendar exactly once. For historical reasons the symbol d is used as the separator of words in the calendar. 

The BerOilGasDiamondBank management wants to show that all its branches are equally important to it, that's why the order of their appearance in the calendar should be following: if we "glue"(concatinate) all the n / 2 calendar lines (from top to bottom) to make a single line, then the lexicographically minimal line is obtained. No separator character will be used to separate calendar lines. For example, if the lines are "bertown!berville", "newberville!bera", then the resulting line is "bertown!bervillenewberville!bera". In some sense one has to find the lexicographically minimal calendar, where the comparison of calendars happens line by line.

Help BerOilGasDiamondBank and construct the required calendar.

Input

The first line contains an integer n (1 ≤ n ≤ 104, n is even) which is the number of branches. Then follow n lines which are the names of the cities. All the names consist of lowercase Latin letters; their lengths are no less than 1 and no more than 10 symbols. The next line contains a single symbol d (d has an ASCII-code from 33 to 126 inclusively, excluding lowercase Latin letters) which is the separator between words in the calendar lines. It is guaranteed that the calendar is possible to be constructed and all the names are different.

Output

Print n / 2 lines of similar length which are the required calendar. Every line should contain exactly two words and exactly one separator between them. If there are several solutions, print the lexicographically minimal one. The lexicographical comparison of lines is realized by the "<" operator in the modern programming languages.

Examples

Input

4
b
aa
hg
c
.


Output

aa.b
c.hg


Input

2
aa
a
!


Output

a!aa


Input

2
aa
a
|


Output

aa|a
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.math.BigInteger;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.InputMismatchException;

public class SandBox {
	InputReader in;
	PrintWriter out;

	void solve() {
		int N = in.readInt();
		int max_len = 0;
		int min_len = 10;
		
		ArrayList<String> A = new ArrayList<String>();
		for(int i = 0; i < N; i++) {
			String buffer = in.readString();
			
			if(buffer.length() > max_len) {
				max_len = buffer.length();
			}
			if(buffer.length() < min_len) {
				min_len = buffer.length();
			}
			
			A.add(buffer);
		}
		
		int needed_length = max_len + min_len + 1;
		
		char d = in.readCharacter();
		
		Collections.sort(A);
		
		while(A.size() > 0) {
			int a = 0;
			int b = 0;
			
			if(d > 'a') {
				boolean f = true;
				while(f && a < A.size() - 1) {
					f = false;

					if(A.get(a).length() < A.get(a + 1).length()) {
						if(A.get(a).substring(0, A.get(a).length()).equals(A.get(a + 1).substring(0, A.get(a).length()))) {
							++a;
							f = true;
						}
					}
				}
			}
			
			for(int i = 0; i < A.size(); i++) {
				if(a != i && A.get(a).length() + A.get(i).length() + 1 == needed_length) {
					b = i;
					break;
				}
			}
			
			out.println(A.get(a) + d + A.get(b));
			
			A.remove(Math.min(a, b));
			A.remove(Math.max(a, b) - 1);
		}

	}
	
	public static void main(String[] args) {
		new SandBox().run();
	}

	SandBox() {
//		String id = getClass().getName().toLowerCase();
		try {
//			System.setIn(new FileInputStream(id + ".in"));
//			System.setOut(new PrintStream(new FileOutputStream(id + ".out")));
//			System.setIn(new FileInputStream("input.txt"));
//			System.setOut(new PrintStream(new FileOutputStream("output.txt")));
		} catch (Exception e) {
			throw new RuntimeException(e);
		}
		in = new InputReader(System.in);
		out = new PrintWriter(System.out);
	}

	void run() {
//		int testCount = in.readInt();
//		for (int i = 0; i < testCount; i++)
		
		solve();
		exit();
	}

	void exit() {
		out.close();
		System.exit(0);
	}

	static class InputReader {
		InputStream stream;
		byte[] buf = new byte[1024];
		int curChar, numChars;

		InputReader(InputStream stream) {
			this.stream = stream;
		}

		int read() {
			if (numChars == -1)
				throw new InputMismatchException();
			if (curChar >= numChars) {
				curChar = 0;
				try {
					numChars = stream.read(buf);
				} catch (IOException e) {
					throw new InputMismatchException();
				}
				if (numChars <= 0)
					return -1;
			}
			return buf[curChar++];
		}

		int readInt() {
			int c = read();
			while (isSpaceChar(c))
				c = read();
			int sgn = 1;
			if (c == '-') {
				sgn = -1;
				c = read();
			}
			int res = 0;
			do {
				if (c < '0' || c > '9')
					throw new InputMismatchException();
				res *= 10;
				res += c - '0';
				c = read();
			} while (!isSpaceChar(c));
			return res * sgn;
		}

		long readLong() {
			int c = read();
			while (isSpaceChar(c))
				c = read();
			int sgn = 1;
			if (c == '-') {
				sgn = -1;
				c = read();
			}
			long res = 0;
			do {
				if (c < '0' || c > '9')
					throw new InputMismatchException();
				res *= 10;
				res += c - '0';
				c = read();
			} while (!isSpaceChar(c));
			return res * sgn;
		}

		String readString() {
			int c = read();
			while (isSpaceChar(c))
				c = read();
			StringBuffer res = new StringBuffer();
			do {
				res.appendCodePoint(c);
				c = read();
			} while (!isSpaceChar(c));
			return res.toString();
		}

		boolean isSpaceChar(int c) {
			return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
		}

		String readLine0() {
			StringBuffer buf = new StringBuffer();
			int c = read();
			while (c != '\n' && c != -1) {
				if (c != '\r')
					buf.appendCodePoint(c);
				c = read();
			}
			return buf.toString();
		}

		String readLine() {
			String s = readLine0();
			while (s.trim().length() == 0)
				s = readLine0();
			return s;
		}

		String readLine(boolean ignoreEmptyLines) {
			if (ignoreEmptyLines)
				return readLine();
			else
				return readLine0();
		}

		BigInteger readBigInteger() {
			try {
				return new BigInteger(readString());
			} catch (NumberFormatException e) {
				throw new InputMismatchException();
			}
		}

		char readCharacter() {
			int c = read();
			while (isSpaceChar(c))
				c = read();
			return (char) c;
		}

		double readDouble() {
			int c = read();
			while (isSpaceChar(c))
				c = read();
			int sgn = 1;
			if (c == '-') {
				sgn = -1;
				c = read();
			}
			double res = 0;
			while (!isSpaceChar(c) && c != '.') {
				if (c == 'e' || c == 'E')
					return res * Math.pow(10, readInt());
				if (c < '0' || c > '9')
					throw new InputMismatchException();
				res *= 10;
				res += c - '0';
				c = read();
			}
			if (c == '.') {
				c = read();
				double m = 1;
				while (!isSpaceChar(c)) {
					if (c == 'e' || c == 'E')
						return res * Math.pow(10, readInt());
					if (c < '0' || c > '9')
						throw new InputMismatchException();
					m /= 10;
					res += (c - '0') * m;
					c = read();
				}
			}
			return res * sgn;
		}

		int[] readIntArray(int size) {
			int[] array = new int[size];
			for (int i = 0; i < size; i++)
				array[i] = readInt();
			return array;
		}

		long[] readLongArray(int size) {
			long[] array = new long[size];
			for (int i = 0; i < size; i++)
				array[i] = readLong();
			return array;
		}

		double[] readDoubleArray(int size) {
			double[] array = new double[size];
			for (int i = 0; i < size; i++)
				array[i] = readDouble();
			return array;
		}

		String[] readStringArray(int size) {
			String[] array = new String[size];
			for (int i = 0; i < size; i++)
				array[i] = readString();
			return array;
		}

		char[][] readTable(int rowCount, int columnCount) {
			char[][] table = new char[rowCount][columnCount];
			for (int i = 0; i < rowCount; i++) {
				for (int j = 0; j < columnCount; j++)
					table[i][j] = readCharacter();
			}
			return table;
		}

		void readIntArrays(int[]...arrays) {
			for (int i = 0; i < arrays.length; i++) {
				for (int j = 0; j < arrays[0].length; j++)
					arrays[i][j] = readInt();
			}
		}
	}
}