public class Main {

    public static final int MOD998 = 998244353;
    public static final int MOD100 = 1000000007;

    static int nextNum = 1;

    public static void main(String[] args) throws Exception {
        ContestScanner sc = new ContestScanner();
        ContestPrinter cp = new ContestPrinter();
        int H = sc.nextInt();
        int W = sc.nextInt();
        int[][] ans = new int[H][W];
        boolean suc = solveC(ans, H, W, 0, 0);
        if (suc) {
            cp.println(nextNum - 1);
            for (int i = 0; i < H; i++) {
                for (int j = 0; j < W; j++) {
                    cp.print(ans[i][j]);
                    cp.print(j == W - 1 ? "\n" : " ");
                }
            }
        } else {
            cp.println(-1);
        }
        nextNum = 1;
        suc = solveT(ans, H, W, 0, 0);
        if (suc) {
            cp.println(nextNum - 1);
            for (int i = 0; i < H; i++) {
                for (int j = 0; j < W; j++) {
                    cp.print(ans[i][j]);
                    cp.print(j == W - 1 ? "\n" : " ");
                }
            }
        } else {
            cp.println(-1);
        }
        nextNum = 1;
        suc = solveCT(ans, H, W, 0, 0);
        if (suc) {
            cp.println(nextNum - 1);
            for (int i = 0; i < H; i++) {
                for (int j = 0; j < W; j++) {
                    cp.print(ans[i][j]);
                    cp.print(j == W - 1 ? "\n" : " ");
                }
            }
        } else {
            cp.println(-1);
        }
        cp.close();
    }

    static void placeVertC(int[][] mat, int hmin, int hmax, int w, int len1, int len2) {
        for (int i = hmin; i <= hmax; i++) {
            mat[i][w] = nextNum;
        }
        for (int i = Math.min(w, w + len1); i <= Math.max(w, w + len1); i++) {
            mat[hmin][i] = nextNum;
        }
        for (int i = Math.min(w, w + len2); i <= Math.max(w, w + len2); i++) {
            mat[hmax][i] = nextNum;
        }
        nextNum++;
    }

    static void placeHoriC(int[][] mat, int wmin, int wmax, int h, int len1, int len2) {
        for (int i = wmin; i <= wmax; i++) {
            mat[h][i] = nextNum;
        }
        for (int i = Math.min(h, h + len1); i <= Math.max(h, h + len1); i++) {
            mat[i][wmin] = nextNum;
        }
        for (int i = Math.min(h, h + len2); i <= Math.max(h, h + len2); i++) {
            mat[i][wmax] = nextNum;
        }
        nextNum++;
    }

    static void placeT(int[][] mat, int h, int w, int up, int down, int left, int right) {
        for (int i = 0; i <= up; i++) {
            mat[h - i][w] = nextNum;
        }
        for (int i = 0; i <= down; i++) {
            mat[h + i][w] = nextNum;
        }
        for (int i = 0; i <= left; i++) {
            mat[h][w - i] = nextNum;
        }
        for (int i = 0; i <= right; i++) {
            mat[h][w + i] = nextNum;
        }
        nextNum++;
    }

    static boolean solveC(int[][] mat, int h, int w, int hoff, int woff) {
        if (h > w) {
            int[][] temp = new int[w][h];
            boolean flag = solveC(temp, w, h, 0, 0);
            if (!flag) {
                return false;
            }
            for (int i = 0; i < h; i++) {
                for (int j = 0; j < w; j++) {
                    mat[i + hoff][j + woff] = temp[j][i];
                }
            }
            return true;
        }
        if (h == 2 || h == 3 && w % 2 == 1) {
            return false;
        } else if (h == 3) {
            for (int i = 0; i < w; i += 2) {
                boolean flag = i % 4 == 0;
                if (i == 0) {
                    placeHoriC(mat, 0 + woff, 2 + woff, 0 + hoff, 2, 1);
                } else if (i == w - 2) {
                    placeHoriC(mat, w - 3 + woff, w - 1 + woff, (flag ? 0 : 2) + hoff, flag ? 1 : -1, flag ? 2 : -2);
                } else {
                    placeHoriC(mat, i - 1 + woff, i + 2 + woff, (flag ? 0 : 2) + hoff, flag ? 1 : -1, flag ? 1 : -1);
                }
            }
        } else if (h == 4) {
            placeVertC(mat, 0 + hoff, 2 + hoff, 0 + woff, w - 1, w - 2);
            placeVertC(mat, 1 + hoff, 3 + hoff, w - 1 + woff, -(w - 2), -(w - 1));
        } else {
            placeHoriC(mat, 0 + woff, w - 1 + woff, 0 + hoff, h - 1, h - 1);
            solveC(mat, h - 1, w - 2, hoff + 1, woff + 1);
        }
        return true;
    }

    static boolean solveT(int[][] mat, int h, int w, int hoff, int woff) {
        if (h > w) {
            int[][] temp = new int[w][h];
            boolean flag = solveT(temp, w, h, 0, 0);
            if (!flag) {
                return false;
            }
            for (int i = 0; i < h; i++) {
                for (int j = 0; j < w; j++) {
                    mat[i + hoff][j + woff] = temp[j][i];
                }
            }
            return true;
        }
        if (h == 2 || h == 3 && w <= 5) {
            return false;
        } else if (h == 3) {
            placeT(mat, 1 + hoff, 0 + woff, 1, 1, 0, 1);
            placeT(mat, 1 + hoff, w - 1 + woff, 1, 1, w - 5, 0);
            placeT(mat, 0 + hoff, 2 + woff, 0, 1, 1, w - 4);
            placeT(mat, 2 + hoff, 3 + woff, 1, 0, 2, w - 5);
        } else if (h == 4) {
            placeT(mat, 0 + hoff, 1 + woff, 0, 1, 1, w - 3);
            placeT(mat, 1 + hoff, w - 1 + woff, 1, 1, w - 3, 0);
            placeT(mat, 2 + hoff, 0 + woff, 1, 1, 0, w - 3);
            placeT(mat, 3 + hoff, w - 2 + woff, 1, 0, w - 3, 1);
        } else if (h == 5) {
            placeT(mat, 0 + hoff, w - 2 + woff, 0, 1, w - 3, 1);
            placeT(mat, 1 + hoff, 0 + woff, 1, 1, 0, w - 3);
            placeT(mat, 2 + hoff, w - 1 + woff, 1, 1, w - 3, 0);
            placeT(mat, 3 + hoff, 1 + woff, 1, 0, 1, w - 4);
            placeT(mat, 4 + hoff, w - 2 + woff, 1, 0, w - 2, 1);
        } else {
            placeT(mat, 0 + woff, 2 + woff, 0, 1, 1, w - 4);
            placeT(mat, 1 + woff, 0 + woff, 1, h - 2, 0, 1);
            placeT(mat, 1 + woff, w - 1 + woff, 1, h - 2, w - 4, 0);
            solveT(mat, h - 2, w - 2, hoff + 2, woff + 1);
        }
        return true;
    }

    static boolean solveCT(int[][] mat, int h, int w, int hoff, int woff) {
        if (h > w) {
            int[][] temp = new int[w][h];
            boolean flag = solveCT(temp, w, h, 0, 0);
            if (!flag) {
                return false;
            }
            for (int i = 0; i < h; i++) {
                for (int j = 0; j < w; j++) {
                    mat[i + hoff][j + woff] = temp[j][i];
                }
            }
            return true;
        }
        if (h == 2) {
            return false;
        } else if (h == 3) {
            placeVertC(mat, 0 + hoff, 2 + hoff, 0 + woff, w - 2, w - 2);
            placeT(mat, 1 + hoff, w - 1 + woff, 1, 1, w - 2, 0);
        } else if (h == 4 && w == 4) {
            placeT(mat, 0 + hoff, 2 + woff, 0, 1, 2, 1);
            placeT(mat, 2 + hoff, 3 + woff, 1, 1, 2, 0);
            placeVertC(mat, 1 + hoff, 3 + hoff, 0 + woff, 1, 2);
        } else {
            placeHoriC(mat, 0 + woff, w - 1 + woff, 0 + hoff, h - 1, h - 1);
            solveCT(mat, h - 1, w - 2, hoff + 1, woff + 1);
        }
        return true;
    }

    static class ContestScanner {
        private final java.io.InputStream in;
        private final byte[] buffer = new byte[1024];
        private int ptr = 0;
        private int buflen = 0;

        private static final long LONG_MAX_TENTHS = 922337203685477580L;
        private static final int LONG_MAX_LAST_DIGIT = 7;
        private static final int LONG_MIN_LAST_DIGIT = 8;

        public ContestScanner(java.io.InputStream in) {
            this.in = in;
        }

        public ContestScanner() {
            this(System.in);
        }

        private boolean hasNextByte() {
            if (ptr < buflen) {
                return true;
            } else {
                ptr = 0;
                try {
                    buflen = in.read(buffer);
                } catch (java.io.IOException e) {
                    e.printStackTrace();
                }
                if (buflen <= 0) {
                    return false;
                }
            }
            return true;
        }

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

        private static boolean isPrintableChar(int c) {
            return 33 <= c && c <= 126;
        }

        public boolean hasNext() {
            while (hasNextByte() && !isPrintableChar(buffer[ptr]))
                ptr++;
            return hasNextByte();
        }

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

        public long nextLong() {
            if (!hasNext())
                throw new java.util.NoSuchElementException();
            long n = 0;
            boolean minus = false;
            int b = readByte();
            if (b == '-') {
                minus = true;
                b = readByte();
            }
            if (b < '0' || '9' < b) {
                throw new NumberFormatException();
            }
            while (true) {
                if ('0' <= b && b <= '9') {
                    int digit = b - '0';
                    if (n >= LONG_MAX_TENTHS) {
                        if (n == LONG_MAX_TENTHS) {
                            if (minus) {
                                if (digit <= LONG_MIN_LAST_DIGIT) {
                                    n = -n * 10 - digit;
                                    b = readByte();
                                    if (!isPrintableChar(b)) {
                                        return n;
                                    } else if (b < '0' || '9' < b) {
                                        throw new NumberFormatException(
                                                String.format("%d%s... is not number", n, Character.toString(b)));
                                    }
                                }
                            } else {
                                if (digit <= LONG_MAX_LAST_DIGIT) {
                                    n = n * 10 + digit;
                                    b = readByte();
                                    if (!isPrintableChar(b)) {
                                        return n;
                                    } else if (b < '0' || '9' < b) {
                                        throw new NumberFormatException(
                                                String.format("%d%s... is not number", n, Character.toString(b)));
                                    }
                                }
                            }
                        }
                        throw new ArithmeticException(
                                String.format("%s%d%d... overflows long.", minus ? "-" : "", n, digit));
                    }
                    n = n * 10 + digit;
                } else if (b == -1 || !isPrintableChar(b)) {
                    return minus ? -n : n;
                } else {
                    throw new NumberFormatException();
                }
                b = readByte();
            }
        }

        public int nextInt() {
            long nl = nextLong();
            if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE)
                throw new NumberFormatException();
            return (int) nl;
        }

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

        public long[] nextLongArray(int length) {
            long[] array = new long[length];
            for (int i = 0; i < length; i++)
                array[i] = this.nextLong();
            return array;
        }

        public long[] nextLongArray(int length, java.util.function.LongUnaryOperator map) {
            long[] array = new long[length];
            for (int i = 0; i < length; i++)
                array[i] = map.applyAsLong(this.nextLong());
            return array;
        }

        public int[] nextIntArray(int length) {
            int[] array = new int[length];
            for (int i = 0; i < length; i++)
                array[i] = this.nextInt();
            return array;
        }

        public int[][] nextIntArrayMulti(int length, int width) {
            int[][] arrays = new int[width][length];
            for (int i = 0; i < length; i++) {
                for (int j = 0; j < width; j++)
                    arrays[j][i] = this.nextInt();
            }
            return arrays;
        }

        public int[] nextIntArray(int length, java.util.function.IntUnaryOperator map) {
            int[] array = new int[length];
            for (int i = 0; i < length; i++)
                array[i] = map.applyAsInt(this.nextInt());
            return array;
        }

        public double[] nextDoubleArray(int length) {
            double[] array = new double[length];
            for (int i = 0; i < length; i++)
                array[i] = this.nextDouble();
            return array;
        }

        public double[] nextDoubleArray(int length, java.util.function.DoubleUnaryOperator map) {
            double[] array = new double[length];
            for (int i = 0; i < length; i++)
                array[i] = map.applyAsDouble(this.nextDouble());
            return array;
        }

        public long[][] nextLongMatrix(int height, int width) {
            long[][] mat = new long[height][width];
            for (int h = 0; h < height; h++)
                for (int w = 0; w < width; w++) {
                    mat[h][w] = this.nextLong();
                }
            return mat;
        }

        public int[][] nextIntMatrix(int height, int width) {
            int[][] mat = new int[height][width];
            for (int h = 0; h < height; h++)
                for (int w = 0; w < width; w++) {
                    mat[h][w] = this.nextInt();
                }
            return mat;
        }

        public double[][] nextDoubleMatrix(int height, int width) {
            double[][] mat = new double[height][width];
            for (int h = 0; h < height; h++)
                for (int w = 0; w < width; w++) {
                    mat[h][w] = this.nextDouble();
                }
            return mat;
        }

        public char[][] nextCharMatrix(int height, int width) {
            char[][] mat = new char[height][width];
            for (int h = 0; h < height; h++) {
                String s = this.next();
                for (int w = 0; w < width; w++) {
                    mat[h][w] = s.charAt(w);
                }
            }
            return mat;
        }
    }

    static class ContestPrinter extends java.io.PrintWriter {
        public ContestPrinter(java.io.PrintStream stream) {
            super(stream);
        }

        public ContestPrinter() {
            super(System.out);
        }

        private static String dtos(double x, int n) {
            StringBuilder sb = new StringBuilder();
            if (x < 0) {
                sb.append('-');
                x = -x;
            }
            x += Math.pow(10, -n) / 2;
            sb.append((long) x);
            sb.append(".");
            x -= (long) x;
            for (int i = 0; i < n; i++) {
                x *= 10;
                sb.append((int) x);
                x -= (int) x;
            }
            return sb.toString();
        }

        @Override
        public void print(float f) {
            super.print(dtos(f, 20));
        }

        @Override
        public void println(float f) {
            super.println(dtos(f, 20));
        }

        @Override
        public void print(double d) {
            super.print(dtos(d, 20));
        }

        @Override
        public void println(double d) {
            super.println(dtos(d, 20));
        }

        public void printArray(int[] array, String separator) {
            int n = array.length;
            for (int i = 0; i < n - 1; i++) {
                super.print(array[i]);
                super.print(separator);
            }
            super.println(array[n - 1]);
        }

        public void printArray(int[] array) {
            this.printArray(array, " ");
        }

        public void printArray(int[] array, String separator, java.util.function.IntUnaryOperator map) {
            int n = array.length;
            for (int i = 0; i < n - 1; i++) {
                super.print(map.applyAsInt(array[i]));
                super.print(separator);
            }
            super.println(map.applyAsInt(array[n - 1]));
        }

        public void printArray(int[] array, java.util.function.IntUnaryOperator map) {
            this.printArray(array, " ", map);
        }

        public void printArray(long[] array, String separator) {
            int n = array.length;
            for (int i = 0; i < n - 1; i++) {
                super.print(array[i]);
                super.print(separator);
            }
            super.println(array[n - 1]);
        }

        public void printArray(long[] array) {
            this.printArray(array, " ");
        }

        public void printArray(long[] array, String separator, java.util.function.LongUnaryOperator map) {
            int n = array.length;
            for (int i = 0; i < n - 1; i++) {
                super.print(map.applyAsLong(array[i]));
                super.print(separator);
            }
            super.println(map.applyAsLong(array[n - 1]));
        }

        public void printArray(long[] array, java.util.function.LongUnaryOperator map) {
            this.printArray(array, " ", map);
        }

    }
}