Problem: This is the easy version of the problem. The difference between the versions is in the number of possible operations that can be made. You can make hacks if and only if you solved both versions of the problem.

You are given a binary table of size n × m. This table consists of symbols 0 and 1.

You can make such operation: select 3 different cells that belong to one 2 × 2 square and change the symbols in these cells (change 0 to 1 and 1 to 0).

Your task is to make all symbols in the table equal to 0. You are allowed to make at most 3nm operations. You don't need to minimize the number of operations.

It can be proved that it is always possible.

Input

The first line contains a single integer t (1 ≤ t ≤ 5000) — the number of test cases. The next lines contain descriptions of test cases.

The first line of the description of each test case contains two integers n, m (2 ≤ n, m ≤ 100).

Each of the next n lines contains a binary string of length m, describing the symbols of the next row of the table.

It is guaranteed that the sum of nm for all test cases does not exceed 20000.

Output

For each test case print the integer k (0 ≤ k ≤ 3nm) — the number of operations.

In the each of the next k lines print 6 integers x_1, y_1, x_2, y_2, x_3, y_3 (1 ≤ x_1, x_2, x_3 ≤ n, 1 ≤ y_1, y_2, y_3 ≤ m) describing the next operation. This operation will be made with three cells (x_1, y_1), (x_2, y_2), (x_3, y_3). These three cells should be different. These three cells should belong into some 2 × 2 square.

Example

Input


5
2 2
10
11
3 3
011
101
110
4 4
1111
0110
0110
1111
5 5
01011
11001
00010
11011
10000
2 3
011
101


Output


1
1 1 2 1 2 2
2 
2 1 3 1 3 2
1 2 1 3 2 3
4
1 1 1 2 2 2 
1 3 1 4 2 3
3 2 4 1 4 2
3 3 4 3 4 4
4
1 2 2 1 2 2 
1 4 1 5 2 5 
4 1 4 2 5 1
4 4 4 5 3 4
2
1 3 2 2 2 3
1 2 2 1 2 2

Note

In the first test case, it is possible to make only one operation with cells (1, 1), (2, 1), (2, 2). After that, all symbols will be equal to 0.

In the second test case:

  * operation with cells (2, 1), (3, 1), (3, 2). After it the table will be: 
    
          
    011  
    001  
    000  
    

  * operation with cells (1, 2), (1, 3), (2, 3). After it the table will be: 
    
          
    000  
    000  
    000  
    




In the fifth test case:

  * operation with cells (1, 3), (2, 2), (2, 3). After it the table will be: 
    
          
    010  
    110  
    

  * operation with cells (1, 2), (2, 1), (2, 2). After it the table will be: 
    
          
    000  
    000  
    

Solution (in JAVA):

Solution:
//package cf684;

import java.io.*;
import java.util.*;
import java.util.function.Function;
import java.util.stream.Collectors;

// What's the smallest input?
// Check * for int/long overflow.
// Check / for accidental rounding.
// Are you using doubles? Can you avoid it?
// Never compare after taking mod.
// Mod the final result.
// Initialize globals in solve() unless they are independent of the problem input.
// Check for local/global name conflicts (n?).
// Check initial values for max/min (not Integer.MIN_VALUE for long).
public class C {
    static Random rand;
    static boolean MULTIPLE_CASES = true;
    static boolean CONSTRUCTIVE = false;
    static long MOD = (long) 1e9 + 7;
    static long BIG = (long) 2e9 + 10;

    public static void solve(Reader in, PrintWriter out) {
        int n = in.ni(), m = in.ni();
        char[][] arr = new char[n][m];
        for (int i = 0; i < n; i++) arr[i] = in.next().toCharArray();

        List<Operation> ops = new ArrayList<>();
        for (int i = 0; i < n-1; i++) {
            for (int j = 0; j < m; j += 2) {
                if (j == m - 1) j--;
                if (arr[i][j] == '1' || arr[i][j+1] == '1') {
                    if (arr[i][j] == arr[i][j+1]) {
                        apply(new Operation(i, j, i, j+1, i+1, j), ops, arr);
                    } else if (arr[i][j] == '1') {
                        apply(new Operation(i, j, i+1, j, i+1, j+1), ops, arr);
                    } else {
                        insist(arr[i][j+1] == '1');
                        apply(new Operation(i, j+1, i+1, j, i+1, j+1), ops, arr);
                    }
                }
            }
        }

        // last row
        for (int j = 0; j < m; j += 2) {
            if (j == m - 1) j--;
            int i = n-1;
            if (arr[i][j] == '1' || arr[i][j + 1] == '1') {
                if (arr[i][j] == arr[i][j + 1]) {
                    apply(new Operation(i, j, i-1, j, i-1, j+1), ops,arr);
                    apply(new Operation(i-1, j, i-1, j+1, i, j+1), ops, arr);
                } else if (arr[i][j] == '1') {
                    apply(new Operation(i, j, i - 1, j, i, j + 1), ops, arr);
                    apply(new Operation(i, j, i-1, j, i-1, j+1), ops, arr);
                    apply(new Operation(i, j, i, j+1, i-1, j+1), ops, arr);
                } else {
                    insist(arr[i][j + 1] == '1');
                    apply(new Operation(i, j, i - 1, j, i, j + 1), ops, arr);
                    apply(new Operation(i, j, i, j+1, i-1, j+1), ops, arr);
                    apply(new Operation(i-1, j, i-1, j+1, i, j+1), ops, arr);
                }
            }
        }

        out.println(ops.size());
        for (Operation op : ops) out.println(op.toString());
    }

    static class Operation {
        int x1, y1, x2, y2, x3, y3;

        public Operation(int x1, int y1, int x2, int y2, int x3, int y3) {
            this.x1 = x1;
            this.y1 = y1;
            this.x2 = x2;
            this.y2 = y2;
            this.x3 = x3;
            this.y3 = y3;
        }

        @Override
        public String toString() {
            return String.format("%d %d %d %d %d %d", x1+1, y1+1, x2+1, y2+1, x3+1, y3+1);
        }
    }

    static void apply(Operation op, List<Operation> ops, char[][] arr) {
        arr[op.x1][op.y1] = flip(arr[op.x1][op.y1]);
        arr[op.x2][op.y2] = flip(arr[op.x2][op.y2]);
        arr[op.x3][op.y3] = flip(arr[op.x3][op.y3]);
        ops.add(op);
    }

    static char flip(char c) {
        if (c == '0') return '1';
        return '0';
    }

    static boolean check(char[][] arr) {
        int n = arr.length;
        int m = arr[0].length;
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < m; j++) {
                if (arr[i][j] != '0') return false;
            }
        }
        return true;
    }

    public static void main(String[] args) throws IOException {
        Reader in = null;
        PrintWriter out = null;
        for (String arg : args) {
            if (arg.startsWith("input")) {
                in = new Reader(arg);
            } else if (arg.startsWith("output")) {
                out = new PrintWriter(new FileWriter(arg));
            }
        }
        if (in == null) in = new Reader();
        if (out == null) out = new PrintWriter(new OutputStreamWriter(System.out));

        if (MULTIPLE_CASES) {
            int tests = in.ni();
            for (int t = 0; t < tests; t++) {
                solve(in, out);
            }
        } else {
            solve(in, out);
        }

        out.flush();
    }

    static class Tester {
        public static void main(String[] args) throws IOException {
            Validator validator = new Validator();

            File currentDir = new File(".");
            long before;
            long after;
            for (File inputFile : Arrays.stream(currentDir.listFiles())
                    .sorted(Comparator.comparing(File::getName))
                    .collect(Collectors.toList())) {
                if (!inputFile.getName().startsWith("input")
                        || inputFile.getName().contains("sight")
                        || inputFile.getName().contains("big")) continue;
                System.out.println("Test file: " + inputFile.getName());

                before = System.nanoTime();
                String outputFileName = "output" + inputFile.getName().substring(5);
                C.main(new String[]{inputFile.getName(), outputFileName});
                after = System.nanoTime();

                File outputFile = new File(outputFileName);
                if (!outputFile.exists()) {
                    throw new IllegalStateException("Missing output file " + outputFile);
                }

                // TODO if verifier is implemented, remove this
                if (CONSTRUCTIVE) {
                    System.out.println("INPUT:");
                    printFile(inputFile);
                    System.out.printf("\nOUTPUT: (%d milliseconds)\n", (after - before) / 1000000L);
                    printFile(outputFile);
                    continue;
                }

                if (validator.validate(inputFile, outputFile)) {
                    System.out.printf("OK (%d milliseconds)\n", (after - before) / 1000000L);
                } else {
                    System.out.println("FAILED");
                    System.out.println("\nInput: ");
                    printFile(inputFile);
                    System.out.println("\nIncorrect Output: ");
                    printFile(outputFile);
                    return;
                }
            }
            System.out.println("\n-----------------\n");

            File sightTestInput = new File("input-sight");
            if (sightTestInput.exists()) {
                System.out.println("Running sight test... Input:");
                printFile(sightTestInput);
                before = System.nanoTime();
                System.out.println("\nOutput: ");
                C.main(new String[]{"input-sight"});
                after = System.nanoTime();
                System.out.printf("(%d milliseconds)\n", (after - before) / 1000000L);
                System.out.println("\n-----------------\n");
            }

            File bigTestInput = new File("input-big");
            if (bigTestInput.exists()) {
                System.out.println("Running big test...");
                before = System.nanoTime();
                C.main(new String[]{"input-big"});
                after = System.nanoTime();
                System.out.printf("(%d milliseconds)\n", (after - before) / 1000000L);
            }
        }

        static void printFile(File file) throws FileNotFoundException {
            BufferedReader reader = new BufferedReader(new FileReader(file));
            reader.lines().forEach(System.out::println);
        }
    }

    static class Validator {
        boolean validate(File inputFile, File outputFile) throws IOException {
            File expectedOutputFile = new File("expected-output" + inputFile.getName().substring(5));
            if (CONSTRUCTIVE || !expectedOutputFile.exists()) {
                return validateManual(inputFile, outputFile);
            }
            return areSame(outputFile, expectedOutputFile);
        }

        private boolean validateManual(File inputFile, File outputFile) throws IOException {
            if (CONSTRUCTIVE) {
                // Validate output against input
                Reader inputReader = new Reader(inputFile.getName());
                Reader outputReader = new Reader(outputFile.getName());

                // TODO implement manual validation

                throw new IllegalStateException("Missing expected output file");
            } else {
                File naiveOutput = new File("naive-" + outputFile.getName());
                Naive.main(new String[]{inputFile.getName(), naiveOutput.getName()});

                return areSame(outputFile, naiveOutput);
            }
        }

        private boolean areSame(File file1, File file2) throws IOException {
            BufferedReader reader1 = new BufferedReader(new FileReader(file1));
            BufferedReader reader2 = new BufferedReader(new FileReader(file2));

            String line1;
            while ((line1 = reader1.readLine()) != null) {
                String line2 = reader2.readLine();
                if (line2 == null) line2 = ""; // ok if one has an extra newline
                if (!line1.trim().equals(line2.trim())) {
                    return false;
                }
            }
            String line2;
            while ((line2 = reader2.readLine()) != null) {
                if (!line2.trim().isEmpty()) {
                    return false;
                }
            }
            return true;
        }

    }

    static class Naive {
        public static void solveNaive(Reader in, PrintWriter out) {
            throw new IllegalStateException("missing expected output file");
        }

        public static void main(String[] args) throws IOException {
            Reader in = null;
            PrintWriter out = null;
            for (String arg : args) {
                if (arg.startsWith("input")) {
                    in = new Reader(arg);
                } else if (arg.startsWith("naive-output")) {
                    out = new PrintWriter(new FileWriter(arg));
                }
            }
            if (in == null) in = new Reader();
            if (out == null) out = new PrintWriter(new OutputStreamWriter(System.out));

            int tests = in.ni();
            for (int t = 0; t < tests; t++) {
                solveNaive(in, out);
            }

            out.flush();
            out.close();
        }
    }

    static boolean isPowerOfTwo(int x) {
        return x > 0 & (x & (x - 1)) == 0;
    }

    static int gcd(int a, int b) {
        return b == 0 ? a : gcd(b, a % b);
    }

    static void ruffleSort(int[] a) {
        int n = a.length;
        for (int i = 0; i < n; i++) {
            int oi = rand.nextInt(n), temp = a[oi];
            a[oi] = a[i];
            a[i] = temp;
        }
        Arrays.sort(a);
    }

    static void ruffleSort(long[] a) {
        int n = a.length;
        for (int i = 0; i < n; i++) {
            int oi = rand.nextInt(n);
            long temp = a[oi];
            a[oi] = a[i];
            a[i] = temp;
        }
        Arrays.sort(a);
    }

    ///////////////////////////////////
    //////////   FAST PAIR   //////////
    ///////////////////////////////////

    // Works on -1e9 <= x, y <= 1e9
    static long pair(int x, int y) {
        x = (int) BIG / 2 - x;
        y = (int) BIG / 2 - y;
        return x * BIG + y;
    }

    static int x(long pair) {
        return (int) BIG / 2 - (int) (pair / BIG);
    }

    static int y(long pair) {
        return (int) BIG / 2 - (int) (pair % BIG);
    }

    static String str(long pair) {
        return String.format("(%d, %d)", x(pair), y(pair));
    }

    ///////////////////////////////////
    ////////// BINARY SEARCH //////////
    ///////////////////////////////////

    // return highest in range that still returns true
    // T T T F F F F
    // invariant:
    // -    indicator(min) = true
    // -    indicator(max+1) = false
    static int binarySearchHighest(int min, int max, Function<Integer, Boolean> indicator) {
        int a = min;
        int b = max;
        while (a != b) {
            int mid = (a % 2 != b % 2) ? 1 + (a + b) / 2 : (a + b) / 2;
            if (indicator.apply(mid)) {
                a = mid;
            } else {
                b = mid - 1;
            }
        }
        return a;
    }

    // return lowest in range that still returns true
    // F F F F T T T
    // invariant:
    // -    indicator(min-1) = false
    // -    indicator(max) = true
    static int binarySearchLowest(int min, int max, Function<Integer, Boolean> indicator) {
        int a = min;
        int b = max;
        while (a != b) {
            int mid = (a + b) / 2;
            if (indicator.apply(mid)) {
                b = mid;
            } else {
                a = mid + 1;
            }
        }
        return a;
    }

    static void insist(boolean bool) {
        if (!bool) throw new IllegalStateException();
    }

    static class Reader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;

        public Reader() {
            reader = new BufferedReader(new InputStreamReader(System.in), 32768);
            tokenizer = null;
        }

        public Reader(String fileName) throws FileNotFoundException {
            reader = new BufferedReader(new FileReader(fileName));
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }

        public int ni() {
            return Integer.parseInt(next());
        }

        public long nl() {
            return Long.parseLong(next());
        }

        public int[] nis(int n) {
            int[] out = new int[n];
            for (int i = 0; i < n; i++) {
                out[i] = ni();
            }
            return out;
        }

        public long[] nls(int n) {
            long[] out = new long[n];
            for (int i = 0; i < n; i++) {
                out[i] = nl();
            }
            return out;
        }
    }
}