import java.util.ArrayDeque; import java.util.ArrayList; public class Main { public static final int MOD998 = 998244353; public static final int MOD100 = 1000000007; static ArrayList ope = new ArrayList<>(); public static void main(String[] args) throws Exception { ContestScanner sc = new ContestScanner(); ContestPrinter cp = new ContestPrinter(); int T = sc.nextInt(); for (int t = 0; t < T; t++) { solve(sc, cp); } cp.close(); } static void solve(ContestScanner sc, ContestPrinter cp) { ope = new ArrayList<>(); int N = sc.nextInt(); int[][] A = sc.nextIntMatrix(N, N); for (int i = 0; i < N; i++) { for (int j = 0; j < N; j++) { A[i][j]--; } } if (N % 2 == 1) { if (A[N / 2][0] != N / 2 * N) { reverseRow(A, N / 2); } else { reverseRow(A, 0); } if (A[0][N / 2] != N / 2) { reverseCol(A, N / 2); } else { reverseCol(A, 0); } for (int i = 0; i < N; i++) { if (A[N / 2][i] != N / 2 * N + i) { cp.println(-1); return; } if (A[i][N / 2] != i * N + N / 2) { cp.println(-1); return; } } } ArrayDeque revrow = new ArrayDeque<>(); for (int i = 0; i < N / 2; i++) { int[] mem = new int[4]; mem[0] = A[i][0]; mem[1] = A[i][N - 1]; mem[2] = A[N - i - 1][0]; mem[3] = A[N - i - 1][N - 1]; int swap = 0; for (int p = 2; p >= 0; p--) { for (int q = p; q < 3; q++) { if (mem[q] > mem[q + 1]) { int tem = mem[q]; mem[q] = mem[q + 1]; mem[q + 1] = tem; swap++; } } } if (swap % 2 == 1) { revrow.add(i); } } ArrayDeque revcol = new ArrayDeque<>(); for (int i = 1; i < N / 2; i++) { int[] mem = new int[4]; mem[0] = A[0][i]; mem[1] = A[0][N - i - 1]; mem[2] = A[N - 1][i]; mem[3] = A[N - 1][N - i - 1]; int swap = 0; for (int p = 2; p >= 0; p--) { for (int q = p; q < 3; q++) { if (mem[q] > mem[q + 1]) { int tem = mem[q]; mem[q] = mem[q + 1]; mem[q + 1] = tem; swap++; } } } if ((revrow.peek() == 0) == (swap % 2 == 0)) { revcol.add(i); } } boolean rv = false; while (!revrow.isEmpty() || !revcol.isEmpty()) { if (revrow.isEmpty()) { reverseRow(A, 0); rv = !rv; reverseCol(A, revcol.poll()); if (revcol.isEmpty() && rv) { reverseRow(A, 0); rv = !rv; } } else if (revcol.isEmpty()) { reverseRow(A, revrow.poll()); if (!revrow.isEmpty() || rv) { reverseCol(A, 0); rv = !rv; } } else { reverseRow(A, revrow.poll()); reverseCol(A, revcol.poll()); } } if (ope.size() % 2 == 1) { int[][] copy = new int[N][N]; for (int i = 0; i < N; i++) { for (int j = 0; j < N; j++) { int v = A[i][j]; int r = v / N; int c = v % N; copy[j][i] = c * N + r; } } A = copy; } for (int i = 0; i < N / 2; i++) { for (int j = 0; j < N / 2; j++) { int[] mem = new int[4]; int[] memcopy = new int[4]; mem[0] = A[i][j]; mem[1] = A[i][N - j - 1]; mem[2] = A[N - i - 1][j]; mem[3] = A[N - i - 1][N - j - 1]; System.arraycopy(mem, 0, memcopy, 0, 4); int swap = 0; for (int p = 2; p >= 0; p--) { for (int q = p; q < 3; q++) { if (mem[q] > mem[q + 1]) { int tem = mem[q]; mem[q] = mem[q + 1]; mem[q + 1] = tem; swap++; } } } if (swap % 2 == 1 || mem[0] != i * N + j || mem[1] != i * N + (N - j - 1) || mem[2] != (N - i - 1) * N + j || mem[3] != (N - i - 1) * N + (N - j - 1)) { cp.println(-1); return; } for (int p = 0; p < 4; p++) { for (int q = 0; q < 4; q++) { if (memcopy[q] == mem[p]) { memcopy[q] = p; break; } } } int[][] pats = new int[][] { { i, j, i, j }, { i, N - j - 1, i, N - j - 1 }, { N - i - 1, j, N - i - 1, j }, { N - i - 1, N - j - 1, N - i - 1, N - j - 1 } }; while (memcopy[0] != 0 || memcopy[1] != 1 || memcopy[2] != 2 || memcopy[3] != 3) { int op = -1; if (memcopy[0] == 0) { op = 3; } else if (memcopy[0] == 1) { op = 1; } else if (memcopy[0] == 2) { op = 0; } else { op = 2; } for (int p = 0; p < 4; p++) { if (p % 2 == 0) { reverseRow(A, pats[op][p]); } else { reverseCol(A, pats[op][p]); } } if (op == 0) { int tem = memcopy[0]; memcopy[0] = memcopy[1]; memcopy[1] = memcopy[2]; memcopy[2] = tem; } else if (op == 1) { int tem = memcopy[1]; memcopy[1] = memcopy[0]; memcopy[0] = memcopy[3]; memcopy[3] = tem; } else if (op == 2) { int tem = memcopy[2]; memcopy[2] = memcopy[3]; memcopy[3] = memcopy[0]; memcopy[0] = tem; } else { int tem = memcopy[3]; memcopy[3] = memcopy[2]; memcopy[2] = memcopy[1]; memcopy[1] = tem; } } } } cp.println(ope.size()); for (int i = 0; i < ope.size(); i++) { cp.print(ope.get(i) + (i == ope.size() - 1 ? "\n" : " ")); } for (int i = 0; i < N; i++) { for (int j = 0; j < N; j++) { System.err.print(A[i][j] + " "); } System.err.println(); } } static void reverseRow(int[][] mat, int row) { ope.add(row + 1); int i = 0; int j = mat[row].length - 1; while (i < j) { int tem = mat[row][i]; mat[row][i] = mat[row][j]; mat[row][j] = tem; i++; j--; } } static void reverseCol(int[][] mat, int col) { ope.add(col + 1); int i = 0; int j = mat.length - 1; while (i < j) { int tem = mat[i][col]; mat[i][col] = mat[j][col]; mat[j][col] = tem; i++; j--; } } 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); } } }