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:
// package Practice.CF333;
import java.io.*;
import java.util.*;

/*
    Author - Ribhav
    MADE ON - 12/21/2018
*/

public class CF334A { 
    static FastReader s;
    static PrintWriter out;
    static String INPUT = "4";

    public static void main (String[] args) {
        long time = System.currentTimeMillis();
        boolean oj = System.getProperty("ONLINE_JUDGE") != null;
        out = new PrintWriter(System.out);
        s = new FastReader(oj);
        int n = s.nextInt();
        int size = n * n;
        int start = 1;
        int end = size;
        StringBuilder finalAns = new StringBuilder();
        while(start < end){
            StringBuilder ans = new StringBuilder();
            for (int i = 0; i < n/2; i++) {
                ans.append((start + i) + " ");
            }

            start += n/2;

            for (int i = 0; i < n/2; i++) {
                ans.append((end - i) + " ");
            }

            end -= n/2;
            finalAns.append(ans + "\n");

        }

        out.println(finalAns);
        if (!oj) {
            System.out.println(Arrays.deepToString(new Object[] { System.currentTimeMillis() - time + " ms" }));
        }
        out.flush();
    }


    /*----------------------------------------------------------------------------------------------

        Number Theory

    ------------------------------------------------------------------------------------------------
    */


    //    GCD - Using Euclid theorem.
    private static long gcd(long a, long b){
        if(b == 0){
            return a;
        }

        return gcd(b, a % b);
    }

    //    Extended euclidean algorithm
//    Used to solve equations of the form ax + by = gcd(a,b)
//    return array [d, a, b] such that d = gcd(p, q), ap + bq = d
    static long[] extendedEuclidean(long p, long q) {
        if (q == 0)
            return new long[] { p, 1, 0 };

        long[] vals = extendedEuclidean(q, p % q);
        long d = vals[0];
        long a = vals[2];
        long b = vals[1] - (p / q) * vals[2];
        return new long[] { d, a, b };
    }

    // X ^ y mod 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 & 1)==1)
                res = (res * x) % p;

            // y must be even now
            // y = y / 2
            y = y >> 1;
            x = (x * x) % p;
        }
        return res;
    }

    // Returns modulo inverse of a
    // with respect to m using extended
    // Euclid Algorithm. Refer below post for details:
    // https://www.geeksforgeeks.org/multiplicative-inverse-under-modulo-m/
    static long inv(long a, long m)
    {
        long m0 = m, t, q;
        long x0 = 0, x1 = 1;

        if (m == 1)
            return 0;

        // Apply extended Euclid Algorithm
        while (a > 1)
        {
            // q is quotient
            q = a / m;

            t = m;

            // m is remainder now, process
            // same as euclid's algo
            m = a % m;a = t;

            t = x0;

            x0 = x1 - q * x0;

            x1 = t;
        }

        // Make x1 positive
        if (x1 < 0)
            x1 += m0;

        return x1;
    }

    // k is size of num[] and rem[].
    // Returns the smallest number
    // x such that:
    // x % num[0] = rem[0],
    // x % num[1] = rem[1],
    // ..................
    // x % num[k-2] = rem[k-1]
    // Assumption: Numbers in num[] are pairwise
    // coprime (gcd for every pair is 1)
    static long findMinX(long num[], long rem[], long k)
    {
        // Compute product of all numbers
        int prod = 1;
        for (int i = 0; i < k; i++)
            prod *= num[i];

        // Initialize result
        int result = 0;

        // Apply above formula
        for (int i = 0; i < k; i++)
        {
            long pp = prod / num[i];
            result += rem[i] * inv(pp, num[i]) * pp;
        }

        return result % prod;
    }




/*
*   BINARY SEARCH ALGORITHMS
*
*
*
* */

//  Binary search
    private static int binarySearch(int[] arr, int ele){
        int low = 0;
        int high = arr.length - 1;
        while(low <= high){
            int mid = (low + high)/2;
            if(arr[mid] == ele){
                return mid;
            }else if(ele < arr[mid]){
                high = mid - 1;
            }else{
                low = mid + 1;
            }
        }
        return -1;
    }

//    First occurence using binary search

    private static int binarySearchFirstOccurence(int[] arr, int ele){
        int low = 0;
        int high = arr.length - 1;
        int ans = -1;
        while(low <= high){
            int mid = (low + high)/2;
            if(arr[mid] == ele){
                ans = mid;
                high = mid - 1;
            }else if(ele < arr[mid]){
                high = mid - 1;
            }else{
                low = mid + 1;
            }
        }
        return ans;
    }


//    Last occurenece using binary search

    private static int binarySearchLastOccurence(int[] arr, int ele){
        int low = 0;
        int high = arr.length - 1;
        int ans = -1;
        while(low <= high){
            int mid = (low + high)/2;
            if(arr[mid] == ele){
                ans = mid;
                low = mid + 1;
            }else if(ele < arr[mid]){
                high = mid - 1;
            }else{
                low = mid + 1;
            }
        }
        return ans;
    }
    private static class FastReader {
        InputStream is;

        public FastReader(boolean onlineJudge) {
            is = onlineJudge ? System.in : new ByteArrayInputStream(INPUT.getBytes());
        }

        byte[] inbuf = new byte[1024];
        public int lenbuf = 0, ptrbuf = 0;

        int readByte() {
            if (lenbuf == -1)
                throw new InputMismatchException();
            if (ptrbuf >= lenbuf) {
                ptrbuf = 0;
                try {
                    lenbuf = is.read(inbuf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (lenbuf <= 0)
                    return -1;
            }
            return inbuf[ptrbuf++];
        }

        boolean isSpaceChar(int c) {
            return !(c >= 33 && c <= 126);
        }

        int skip() {
            int b;
            while ((b = readByte()) != -1 && isSpaceChar(b))
                ;
            return b;
        }

        double nextDouble() {
            return Double.parseDouble(next());
        }

        char nextChar() {
            return (char) skip();
        }

        String next() {
            int b = skip();
            StringBuilder sb = new StringBuilder();
            while (!(isSpaceChar(b))) { // when nextLine, (isSpaceChar(b) && b != ' ')
                sb.appendCodePoint(b);
                b = readByte();
            }
            return sb.toString();
        }

        String nextLine() {
            int b = skip();
            StringBuilder sb = new StringBuilder();
            while ((!isSpaceChar(b) || b == ' ')) { // when nextLine, (isSpaceChar(b) && b != ' ')
                sb.appendCodePoint(b);
                b = readByte();
            }
            return sb.toString();
        }

        char[] next(int n) {
            char[] buf = new char[n];
            int b = skip(), p = 0;
            while (p < n && !(isSpaceChar(b))) {
                buf[p++] = (char) b;
                b = readByte();
            }
            return n == p ? buf : Arrays.copyOf(buf, p);
        }

        int nextInt() {
            int num = 0, b;
            boolean minus = false;
            while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'))
                ;
            if (b == '-') {
                minus = true;
                b = readByte();
            }

            while (true) {
                if (b >= '0' && b <= '9') {
                    num = num * 10 + (b - '0');
                } else {
                    return minus ? -num : num;
                }
                b = readByte();
            }
        }

        long nextLong() {
            long num = 0;
            int b;
            boolean minus = false;
            while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'))
                ;
            if (b == '-') {
                minus = true;
                b = readByte();
            }

            while (true) {
                if (b >= '0' && b <= '9') {
                    num = num * 10 + (b - '0');
                } else {
                    return minus ? -num : num;
                }
                b = readByte();
            }
        }

        char[][] nextMatrix(int n, int m) {
            char[][] map = new char[n][];
            for (int i = 0; i < n; i++)
                map[i] = next(m);
            return map;
        }

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

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

        int[][] next2DInt(int n, int m) {
            int[][] arr = new int[n][];
            for (int i = 0; i < n; i++) {
                arr[i] = nextIntArray(m);
            }
            return arr;
        }

        long[][] next2DLong(int n, int m) {
            long[][] arr = new long[n][];
            for (int i = 0; i < n; i++) {
                arr[i] = nextLongArray(m);
            }
            return arr;
        }

        int[] shuffle(int[] arr) {
            Random r = new Random();
            for (int i = 1, j; i < arr.length; i++) {
                j = r.nextInt(i);
                arr[i] = arr[i] ^ arr[j];
                arr[j] = arr[i] ^ arr[j];
                arr[i] = arr[i] ^ arr[j];
            }
            return arr;
        }

        int[] uniq(int[] arr) {
            Arrays.sort(arr);
            int[] rv = new int[arr.length];
            int pos = 0;
            rv[pos++] = arr[0];
            for (int i = 1; i < arr.length; i++) {
                if (arr[i] != arr[i - 1]) {
                    rv[pos++] = arr[i];
                }
            }
            return Arrays.copyOf(rv, pos);
        }
    }
}