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.BigDecimal;
    import java.math.RoundingMode;
    import java.util.*;

    import javax.lang.model.type.IntersectionType;
    import javax.swing.text.html.CSS;
    public class codeforces {
        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;
            }
        }
       public static void main(String[] args) throws IOException {
            PrintWriter out = new PrintWriter(System.out);
            InputReader sc=new InputReader(System.in);
            int n=sc.nextInt();
            int a=n*n;
            for(int i=1;i<=n*n/2;i++)
            {
                System.out.print(i+" ");
                if(2*i%n!=0)
                System.out.print(a+" ");
                else
                    System.out.println(a+" ");
                a--;
            }
       }








        static class InputReader {
            private InputStream in;
            private byte[] buffer = new byte[1024];
            private int curbuf;
            private int lenbuf;
            public InputReader(InputStream in) {
                this.in = in;
                this.curbuf = this.lenbuf = 0;
            }
            public boolean hasNextByte() {
                if (curbuf >= lenbuf) {
                    curbuf = 0;
                    try {
                        lenbuf = in.read(buffer);
                    } catch (IOException e) {
                        throw new InputMismatchException();
                    }
                    if (lenbuf <= 0)
                        return false;
                }
                return true;
            }

            private int readByte() {
                if (hasNextByte())
                    return buffer[curbuf++];
                else
                    return -1;
            }

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

            private void skip() {
                while (hasNextByte() && isSpaceChar(buffer[curbuf]))
                    curbuf++;
            }

            public boolean hasNext() {
                skip();
                return hasNextByte();
            }

            public String next() {
                if (!hasNext())
                    throw new NoSuchElementException();
                StringBuilder sb = new StringBuilder();
                int b = readByte();
                while (!isSpaceChar(b)) {
                    sb.appendCodePoint(b);
                    b = readByte();
                }
                return sb.toString();
            }

            public int nextInt() {
                if (!hasNext())
                    throw new NoSuchElementException();
                int c = readByte();
                while (isSpaceChar(c))
                    c = readByte();
                boolean minus = false;
                if (c == '-') {
                    minus = true;
                    c = readByte();
                }
                int res = 0;
                do {
                    if (c < '0' || c > '9')
                        throw new InputMismatchException();
                    res = res * 10 + c - '0';
                    c = readByte();
                } while (!isSpaceChar(c));
                return (minus) ? -res : res;
            }

            public long nextLong() {
                if (!hasNext())
                    throw new NoSuchElementException();
                int c = readByte();
                while (isSpaceChar(c))
                    c = readByte();
                boolean minus = false;
                if (c == '-') {
                    minus = true;
                    c = readByte();
                }
                long res = 0;
                do {
                    if (c < '0' || c > '9')
                        throw new InputMismatchException();
                    res = res * 10 + c - '0';
                    c = readByte();
                } while (!isSpaceChar(c));
                return (minus) ? -res : res;
            }

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

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

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

            public char[][] nextCharMap(int n, int m) {
                char[][] map = new char[n][m];
                for (int i = 0; i < n; i++)
                    map[i] = next().toCharArray();
                return map;
            }
        }
    }
    class SegTree<S> {
        final int MAX;

        final int N;
        final java.util.function.BinaryOperator<S> op;
        final S E;

        final S[] data;

        @SuppressWarnings("unchecked")
        public SegTree(int n, java.util.function.BinaryOperator<S> op, S e) {
            this.MAX = n;
            int k = 1;
            while (k < n) k <<= 1;
            this.N = k;
            this.E = e;
            this.op = op;
            this.data = (S[]) new Object[N << 1];
            java.util.Arrays.fill(data, E);
        }

        public SegTree(S[] dat, java.util.function.BinaryOperator<S> op, S e) {
            this(dat.length, op, e);
            build(dat);
        }

        private void build(S[] dat) {
            int l = dat.length;
            System.arraycopy(dat, 0, data, N, l);
            for (int i = N - 1; i > 0; i--) {
                data[i] = op.apply(data[i << 1 | 0], data[i << 1 | 1]);
            }
        }

        public void set(int p, S x) {
            exclusiveRangeCheck(p);
            data[p += N] = x;
            p >>= 1;
            while (p > 0) {
                data[p] = op.apply(data[p << 1 | 0], data[p << 1 | 1]);
                p >>= 1;
            }
        }

        public S get(int p) {
            exclusiveRangeCheck(p);
            return data[p + N];
        }

        public S prod(int l, int r) {
            if (l > r) {
                throw new IllegalArgumentException(
                        String.format("Invalid range: [%d, %d)", l, r)
                );
            }
            inclusiveRangeCheck(l);
            inclusiveRangeCheck(r);
            S sumLeft = E;
            S sumRight = E;
            l += N; r += N;
            while (l < r) {
                if ((l & 1) == 1) sumLeft = op.apply(sumLeft, data[l++]);
                if ((r & 1) == 1) sumRight = op.apply(data[--r], sumRight);
                l >>= 1; r >>= 1;
            }
            return op.apply(sumLeft, sumRight);
        }

        public S allProd() {
            return data[1];
        }

        public int maxRight(int l, java.util.function.Predicate<S> f) {
            inclusiveRangeCheck(l);
            if (!f.test(E)) {
                throw new IllegalArgumentException("Identity element must satisfy the condition.");
            }
            if (l == MAX) return MAX;
            l += N;
            S sum = E;
            do {
                l >>= Integer.numberOfTrailingZeros(l);
                if (!f.test(op.apply(sum, data[l]))) {
                    while (l < N) {
                        l = l << 1;
                        if (f.test(op.apply(sum, data[l]))) {
                            sum = op.apply(sum, data[l]);
                            l++;
                        }
                    }
                    return l - N;
                }
                sum = op.apply(sum, data[l]);
                l++;
            } while ((l & -l) != l);
            return MAX;
        }

        public int minLeft(int r, java.util.function.Predicate<S> f) {
            inclusiveRangeCheck(r);
            if (!f.test(E)) {
                throw new IllegalArgumentException("Identity element must satisfy the condition.");
            }
            if (r == 0) return 0;
            r += N;
            S sum = E;
            do {
                r--;
                while (r > 1 && (r & 1) == 1) r >>= 1;
                if (!f.test(op.apply(data[r], sum))) {
                    while (r < N) {
                        r = r << 1 | 1;
                        if (f.test(op.apply(data[r], sum))) {
                            sum = op.apply(data[r], sum);
                            r--;
                        }
                    }
                    return r + 1 - N;
                }
                sum = op.apply(data[r], sum);
            } while ((r & -r) != r);
            return 0;
        }

        private void exclusiveRangeCheck(int p) {
            if (p < 0 || p >= MAX) {
                throw new IndexOutOfBoundsException(
                        String.format("Index %d out of bounds for the range [%d, %d).", p, 0, MAX)
                );
            }
        }

        private void inclusiveRangeCheck(int p) {
            if (p < 0 || p > MAX) {
                throw new IndexOutOfBoundsException(
                        String.format("Index %d out of bounds for the range [%d, %d].", p, 0, MAX)
                );
            }
        }
    }
    class MathLib{
        static long fastPow(long a, long b, long mod) {
            if(b == 0)
                return 1L;

            long val = fastPow(a, b/2, mod);
            if(b % 2 == 0)
                return val * val % mod;
            else
                return val * val % mod * a % mod;
        }
        static int LowerBound(int a[], int x) { // x is the target value or key
            int l=-1,r=a.length;
            while(l+1<r) {
                int m=(l+r)>>>1;
                if(a[m]>=x) r=m;
                else l=m;
            }
            return r;
        }
        static int UpperBound(int a[], int x) {// x is the key or target value
            int l=-1,r=a.length;
            while(l+1<r) {
                int m=(l+r)>>>1;
                if(a[m]<=x) l=m;
                else r=m;
            }
            return l+1;
        }
        private static long safe_mod(long x, long m){
            x %= m;
            if(x<0) x += m;
            return x;
        }

        private static long[] inv_gcd(long a, long b){
            a = safe_mod(a, b);
            if(a==0) return new long[]{b,0};

            long s=b, t=a;
            long m0=0, m1=1;
            while(t>0){
                long u = s/t;
                s -= t*u;
                m0 -= m1*u;
                long tmp = s; s = t; t = tmp;
                tmp = m0; m0 = m1; m1 = tmp;
            }
            if(m0<0) m0 += b/s;
            return new long[]{s,m0};
        }

        public static long gcd(long a, long b){
            a = java.lang.Math.abs(a);
            b = java.lang.Math.abs(b);
            return inv_gcd(a, b)[0];
        }
        public static long lcm(long a, long b){
            a = java.lang.Math.abs(a);
            b = java.lang.Math.abs(b);
            return a / gcd(a,b) * b;
        }

        public static long pow_mod(long x, long n, int m){
            assert n >= 0;
            assert m >= 1;
            if(m == 1)return 0L;
            x = safe_mod(x, m);
            long ans = 1L;
            while(n > 0){
                if((n&1) == 1) ans = (ans * x) % m;
                x = (x*x) % m;
                n >>>= 1;
            }
            return ans;
        }

        public static long[] crt(long[] r, long[] m){
            assert(r.length == m.length);
            int n = r.length;

            long r0=0, m0=1;
            for(int i=0; i<n; i++){
                assert(1 <= m[i]);
                long r1 = safe_mod(r[i], m[i]), m1 = m[i];
                if(m0 < m1){
                    long tmp = r0; r0 = r1; r1 = tmp;
                    tmp = m0; m0 = m1; m1 = tmp;
                }
                if(m0%m1 == 0){
                    if(r0%m1 != r1) return new long[]{0,0};
                    continue;
                }

                long[] ig = inv_gcd(m0, m1);
                long g = ig[0], im = ig[1];

                long u1 = m1/g;
                if((r1-r0)%g != 0) return new long[]{0,0};

                long x = (r1-r0) / g % u1 * im % u1;

                r0 += x * m0;
                m0 *= u1;
                if(r0<0) r0 += m0;
                //System.err.printf("%d %d\n", r0, m0);
            }
            return new long[]{r0, m0};
        }
        public static long floor_sum(long n, long m, long a, long b){
            long ans = 0;
            if(a >= m){
                ans += (n-1) * n * (a/m) / 2;
                a %= m;
            }
            if(b >= m){
                ans += n * (b/m);
                b %= m;
            }

            long y_max = (a*n+b) / m;
            long x_max = y_max * m - b;
            if(y_max == 0) return ans;
            ans += (n - (x_max+a-1)/a) * y_max;
            ans += floor_sum(y_max, a, m, (a-x_max%a)%a);
            return ans;
        }

        public static java.util.ArrayList<Long> divisors(long n){
            java.util.ArrayList<Long> divisors = new ArrayList<>();
            java.util.ArrayList<Long> large = new ArrayList<>();

            for(long i=1; i*i<=n; i++) if(n%i==0){
                divisors.add(i);
                if(i*i<n) large.add(n/i);
            }
            for(int p=large.size()-1; p>=0; p--){
                divisors.add(large.get(p));
            }
            return divisors;
        }
    }