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.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.math.BigInteger;
import java.util.* ;
import java.io.* ;
@SuppressWarnings("unused")

//Scanner s = new Scanner(new File("input.txt"));
//s.close();
//PrintWriter writer = new PrintWriter("output.txt");
//writer.close();
//BufferedReader in = new BufferedReader(new InputStreamReader(System.in)) ;

//Scanner in = new Scanner(System.in) ;
//[a-z] = [97-122] ------- [A-Z] = [65-90]

public class cf
{	
	static final int mod = 1000000007 ;
	
	static boolean not_prime[] = new boolean[1000001] ;
	static void sieve() {
		for(int i=2 ; i*i<1000001 ; i++) {
			if(not_prime[i]==false) {
				for(int j=2*i ; j<1000001 ; j+=i) {
					not_prime[j]=true ;
				}
			}
		}not_prime[0]=true ; not_prime[1]=true ;
	}	
	
	public static long bexp(long base , long power)
	{
		long res=1L ;
		
		//base = base%mod ;
		
		while(power>0) {
			if((power&1)==1) {
				res=(res*base);//%mod ;
				power-- ;
			}
			else {
				base=(base*base);//%mod ;
				power>>=1 ;
			}
		}
		
		return res ;
	}

	static long modInverse(long n, long p)
	{
	    return power(n, p - 2, p);
	}
	static long power(long x, long y, long p)
	{
	  
	    // Initialize result
	    long res = 1;
	  
	    // Update x if it is more than or
	    // equal to p
	    x = x % p;
	  
	    while (y > 0) {
	  
	        // If y is odd, multiply x
	        // with result
	        if (y % 2 == 1)
	            res = (res * x) % p;
	  
	        // y must be even now
	        y = y >> 1; // y = y/2
	        x = (x * x) % p;
	    }
	  
	    return res;
	}
	static long nCrModPFermat(int n, int r, long p)
	{
		if(n<r) return 0 ;
	    if (r == 0)
	        return 1;

	    long[] fac = new long[n + 1];
	    fac[0] = 1;
	  
	    for (int i = 1; i <= n; i++)
	        fac[i] = fac[i - 1] * i % p;
	  
	    return (fac[n] * modInverse(fac[r], p) % p
	            * modInverse(fac[n - r], p) % p)
	        % p;
	}
	
	private static long modular_add(long a, long b)
	{
	    return ((a % mod) + (b % mod)) % mod;
	}
	private static long modular_sub(long a, long b)
	{
	    return ((a % mod) - (b % mod) + mod) % mod;
	}
	private static long modular_mult(long a, long b)
	{
	    return ((a % mod) * (b % mod)) % mod;
	}
	
	static long lcm(int a, int b)
	{
		return (a / gcd(a, b)) * b;
	}
	private static long gcd(long a, long b)
	{
		if (b == 0) {
			return a;
		}
		return gcd(b, a % b);
	}

	
    static class FastReader {
        BufferedReader br;
        StringTokenizer st;
 
        public FastReader()
        {
            br = new BufferedReader(
                new InputStreamReader(System.in));
        }
 
        String next()
        {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                }
                catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }
 
        int nextInt() { return Integer.parseInt(next()); }
 
        long nextLong() { return Long.parseLong(next()); }
 
        double nextDouble(){ return Double.parseDouble(next()); };
 
        String nextLine()
        {
            String str = "";
            try {
                str = br.readLine();
            }
            catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }
    }
	
	static HashMap<Integer , ArrayList<Integer>> map = new HashMap<>() ;
	static boolean vis[] ;
	public static void main(String[] args)throws IOException//throws FileNotFoundException
    {
    	FastReader in = new FastReader() ;	
    	StringBuilder op = new StringBuilder() ;
			int n = in.nextInt() ;
			int a[] = new int[(n*n)+1] ;
			for(int i=1 ; i<=n*n ; i++)
				a[i]=i ;
			int left=1 , right=n*n ;
			for(int i=0 ; i<n ; i++)
			{
				for(int j=0 ; j<n/2 ; j++) {
				op.append(left+" "+right+" ");
				left++ ; right-- ;
				}
				op.append("\n");
			}
			System.out.println(op.toString());
    }
}