Problem: Gerald has n younger brothers and their number happens to be even. One day he bought n2 candy bags. One bag has one candy, one bag has two candies, one bag has three candies and so on. In fact, for each integer k from 1 to n2 he has exactly one bag with k candies. 

Help him give n bags of candies to each brother so that all brothers got the same number of candies.

Input

The single line contains a single integer n (n is even, 2 ≤ n ≤ 100) — the number of Gerald's brothers.

Output

Let's assume that Gerald indexes his brothers with numbers from 1 to n. You need to print n lines, on the i-th line print n integers — the numbers of candies in the bags for the i-th brother. Naturally, all these numbers should be distinct and be within limits from 1 to n2. You can print the numbers in the lines in any order. 

It is guaranteed that the solution exists at the given limits.

Examples

Input

2


Output

1 4
2 3

Note

The sample shows Gerald's actions if he has two brothers. In this case, his bags contain 1, 2, 3 and 4 candies. He can give the bags with 1 and 4 candies to one brother and the bags with 2 and 3 to the other brother.

Solution (in JAVA):

Solution:
import java.io.*;
import java.math.*;
import java.util.*;

public class CandyBags_194 {

	public static void main(String[] args) throws IOException {
		// ----------------------------------------------------
		start();
		// ----------------------------------------------------
		int n = nextInt();

		int[][] a = new int[n + 1][n + 1];

		int num = 1;

		for (int i = 1; i < n + 1; i++) {
			for (int j = 1; j < n + 1; j++) {
				a[i][j] = num++;
			}
		}
		for (int j = 1; j <= n; j++) {
			int flag = j;
			for (int i = 1; i <= n; i++) {
				out.print(a[i][flag % n + 1]);
				flag++;
				if (i != n) {
					out.print(" ");
				}
			}
			out.println();
		}

		// ----------------------------------------------------
		end();
		// ----------------------------------------------------
	}

	static BufferedReader br;
	static PrintWriter out;
	static StringTokenizer sc;

	static void start() throws IOException {
		br = new BufferedReader(new InputStreamReader(System.in));
		out = new PrintWriter(new OutputStreamWriter(System.out));
		sc = new StringTokenizer("");
	}

	static void end() throws IOException {
		br.close();
		out.close();
	}

	static String nextString() throws IOException {
		while (!sc.hasMoreTokens()) {
			String s = br.readLine();
			if (s == null) {
				return null;
			}
			sc = new StringTokenizer(s.trim());
		}
		return sc.nextToken();
	}

	static String nextLine() throws IOException {
		String s = br.readLine();
		if (s == null) {
			return null;
		}
		return s;
	}

	static int nextInt() throws IOException {
		return Integer.parseInt(nextString());
	}

	static long nextLong() throws IOException {
		return Long.parseLong(nextString());
	}

	static double nextDouble() throws IOException {
		return Double.parseDouble(nextString());
	}

	BigInteger nextBigInteger() throws IOException {
		return new BigInteger(nextString());
	}

	static int[] nextIntArray(int n) throws IOException {
		int[] a = new int[n];
		for (int i = 0; i < n; i++)
			a[i] = nextInt();
		return a;
	}

	static long[] nextLongArray(int n) throws IOException {
		long[] a = new long[n];
		for (int i = 0; i < n; i++)
			a[i] = nextLong();
		return a;
	}

	static char[] nextCharArray() throws IOException {
		return nextString().toCharArray();
	}

	static String[] nextStringArray(int n) throws IOException {
		String[] a = new String[n];
		for (int i = 0; i < n; i++)
			a[i] = nextString();
		return a;
	}

}