Problem: Pink Floyd are pulling a prank on Roger Waters. They know he doesn't like [walls](https://www.youtube.com/watch?v=YR5ApYxkU-U), he wants to be able to walk freely, so they are blocking him from exiting his room which can be seen as a grid.

Roger Waters has a square grid of size n× n and he wants to traverse his grid from the upper left (1,1) corner to the lower right corner (n,n). Waters can move from a square to any other square adjacent by a side, as long as he is still in the grid. Also except for the cells (1,1) and (n,n) every cell has a value 0 or 1 in it.

Before starting his traversal he will pick either a 0 or a 1 and will be able to only go to cells values in which are equal to the digit he chose. The starting and finishing cells (1,1) and (n,n) are exempt from this rule, he may go through them regardless of picked digit. Because of this the cell (1,1) takes value the letter 'S' and the cell (n,n) takes value the letter 'F'.

For example, in the first example test case, he can go from (1, 1) to (n, n) by using the zeroes on this path: (1, 1), (2, 1), (2, 2), (2, 3), (3, 3), (3, 4), (4, 4)

The rest of the band (Pink Floyd) wants Waters to not be able to do his traversal, so while he is not looking they will invert at most two cells in the grid (from 0 to 1 or vice versa). They are afraid they will not be quick enough and asked for your help in choosing the cells.  Note that you cannot invert cells (1, 1) and (n, n).

We can show that there always exists a solution for the given constraints.

Also note that Waters will pick his digit of the traversal after the band has changed his grid, so he must not be able to reach (n,n) no matter what digit he picks.

Input

Each test contains multiple test cases. The first line contains the number of test cases t (1 ≤ t ≤ 50). Description of the test cases follows.

The first line of each test case contains one integers n (3 ≤ n ≤ 200).

The following n lines of each test case contain the binary grid, square (1, 1) being colored in 'S' and square (n, n) being colored in 'F'.

The sum of values of n doesn't exceed 200.

Output

For each test case output on the first line an integer c (0 ≤ c ≤ 2) — the number of inverted cells.

In i-th of the following c lines, print the coordinates of the i-th cell you inverted. You may not invert the same cell twice.  Note that you cannot invert cells (1, 1) and (n, n).

Example

Input


3
4
S010
0001
1000
111F
3
S10
101
01F
5
S0101
00000
01111
11111
0001F


Output


1
3 4
2
1 2
2 1
0

Note

For the first test case, after inverting the cell, we get the following grid:
    
    
      
    S010  
    0001  
    1001  
    111F  
    

Solution (in JAVA):

Solution:
import java.io.*;
import java.math.*;
import java.util.*;

public class test {

	public static void main(String[] args) {
		int test = fs.nextInt();
//		int test = 1;
		for (int cases = 0; cases < test; cases++) {
			int n = fs.nextInt();
			char ar[][] = new char[n][n];
			for (int i = 0; i < n; i++) {
				String s = fs.next();
				char a[] = s.toCharArray();
				for (int j = 0; j < a.length; j++) {
					ar[i][j] = a[j];
				}
			}
			char x = ar[0][1];
			char y = ar[1][0];
			char z = ar[n - 1][n - 2];
			char a = ar[n - 2][n - 1];
			ArrayList<Pair> al = new ArrayList<Pair>();
			if (x == y && a == z && x != a) {

			} else if (x == y) {
				if (x == a)
					al.add(new Pair(n - 1, n));
				if (x == z) {
					al.add(new Pair(n, n - 1));
				}
			} else if (x != y) {
				if (a == z) {
					if (x == a)
						al.add(new Pair(1, 2));
					else
						al.add(new Pair(2, 1));
				} else {
					if (x != a) {
						al.add(new Pair(1, 2));
						al.add(new Pair(n - 1, n));
					} else if (y != a) {
						al.add(new Pair(2, 1));
						al.add(new Pair(n - 1, n));
					} else if (x != z) {
						al.add(new Pair(1, 2));
						al.add(new Pair(n, n - 1));
					} else if (y != z) {
						al.add(new Pair(2, 1));
						al.add(new Pair(n, n - 1));
					}
				}
			}
			op.print(al.size() + "\n");
			for (Pair pair : al) {
				op.print(pair.first + " " + pair.second + "\n");
			}
			op.flush();
		}

	}

	static void sieve() {
		boolean prime[] = new boolean[101];
		Arrays.fill(prime, true);
		prime[1] = false;
		for (int i = 2; i * i <= prime.length - 1; i++) {
			for (int j = i * i; j <= prime.length - 1; j += i) {
				prime[j] = false;
			}
		}
	}

	static void printArray(int ar[]) {
		Arrays.toString(ar);
	}

	static long expmodulo(long a, long b, long c) {
		long x = 1;
		long y = a;
		while (b > 0) {
			if (b % 2 == 1) {
				x = (x * y) % c;
			}
			y = (y * y) % c; // squaring the base
			b /= 2;
		}
		return (long) x % c;
	}

	static int modInverse(int a, int m) {
		int m0 = m;
		int y = 0, x = 1;

		if (m == 1)
			return 0;

		while (a > 1) {
			int q = a / m;
			int t = m;
			m = a % m;
			a = t;
			t = y;
			y = x - q * y;
			x = t;
		}
		if (x < 0)
			x += m0;
		return x;
	}

	static int countBits(int number) {
		return (int) (Math.log(number) / Math.log(2) + 1);
	}

	static int countDifferentBits(int a, int b) {
		int count = 0;
		for (int i = 0; i < 32; i++) {
			if (((a >> i) & 1) != ((b >> i) & 1)) {
				++count;
			}
		}
		return count;
	}

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

	static void sortMyMapusingValues(HashMap<String, Integer> hm) {

		List<Map.Entry<String, Integer>> capitalList = new LinkedList<>(hm.entrySet());

		Collections.sort(capitalList, new Comparator<Map.Entry<String, Integer>>() {
			public int compare(Map.Entry<String, Integer> o1, Map.Entry<String, Integer> o2) {
				return (o1.getValue()).compareTo(o2.getValue());
			}
		});
		HashMap<String, Integer> result = new HashMap<>();
		for (Map.Entry<String, Integer> entry : capitalList) {
			result.put(entry.getKey(), entry.getValue());
		}
	}

	static boolean ispowerof2(long num) {
		if ((num & (num - 1)) == 0)
			return true;
		return false;
	}

	static void primeFactors(int n) {
		while (n % 2 == 0) {
			System.out.print(2 + " ");
			n /= 2;
		}
		for (int i = 3; i <= Math.sqrt(n); i += 2) {
			while (n % i == 0) {
				System.out.print(i + " ");
				n /= i;
			}
		}
		if (n > 2)
			System.out.print(n);
	}

	static boolean isPrime(long n) {
		// Corner cases
		if (n <= 1)
			return false;
		if (n <= 3)
			return true;
		if (n % 2 == 0 || n % 3 == 0)
			return false;

		long sq = (long) Math.sqrt(n);
		for (int i = 5; i <= sq; i = i + 6)
			if (n % i == 0 || n % (i + 2) == 0)
				return false;

		return true;
	}

	static class Graph {
		HashMap<Integer, LinkedList<Integer>> hm = new HashMap<Integer, LinkedList<Integer>>();

		private void addVertex(int vertex) {
			hm.put(vertex, new LinkedList<>());
		}

		private void addEdge(int source, int dest, boolean bi) {
			if (!hm.containsKey(source))
				addVertex(source);
			if (!hm.containsKey(dest))
				addVertex(dest);
			hm.get(source).add(dest);
			if (bi) {
				hm.get(dest).add(source);
			}
		}

		private boolean uniCycle(int i, HashSet<Integer> visited, int parent) {
			visited.add(i);
			LinkedList<Integer> list = hm.get(i);
			Iterator<Integer> it = list.iterator();
			while (it.hasNext()) {
				Integer integer = (Integer) it.next();
				if (!visited.contains(integer)) {
					if (uniCycle(integer, visited, i))
						return true;
				} else if (integer != parent) {
					return true;
				}
			}
			return false;
		}

		private boolean uniCyclic() {
			HashSet<Integer> visited = new HashSet<Integer>();
			Set<Integer> set = hm.keySet();
			for (Integer integer : set) {
				if (!visited.contains(integer)) {
					if (uniCycle(integer, visited, -1)) {
						return true;
					}
				}
			}
			return false;
		}

		private boolean isbiCycle(int i, HashSet<Integer> visited, HashSet<Integer> countered) {
			if (countered.contains(i))
				return true;
			if (visited.contains(i))
				return false;
			visited.add(i);
			countered.add(i);
			LinkedList<Integer> list = hm.get(i);
			Iterator<Integer> it = list.iterator();
			while (it.hasNext()) {
				Integer integer = (Integer) it.next();
				if (isbiCycle(integer, visited, countered)) {
					return true;
				}
			}
			countered.remove(i);
			return false;
		}

		private boolean isbiCyclic() {
			HashSet<Integer> visited = new HashSet<Integer>();
			HashSet<Integer> countered = new HashSet<Integer>();
			Set<Integer> set = hm.keySet();
			for (Integer integer : set) {
				if (isbiCycle(integer, visited, countered)) {
					return true;
				}
			}
			return false;
		}
	}

	static class Node {
		Node left, right;
		int data;

		public Node(int data) {
			this.data = data;
		}

		public void insert(int val) {
			if (val <= data) {
				if (left == null) {
					left = new Node(val);
				} else {
					left.insert(val);
				}
			} else {
				if (right == null) {
					right = new Node(val);
				} else {
					right.insert(val);
				}
			}
		}

		public boolean contains(int val) {
			if (data == val) {
				return true;
			} else if (val < data) {
				if (left == null) {
					return false;
				} else {
					return left.contains(val);
				}
			} else {
				if (right == null) {
					return false;
				} else {
					return right.contains(val);
				}
			}
		}

		public void inorder() {
			if (left != null) {
				left.inorder();
			}
			System.out.print(data + " ");
			if (right != null) {
				right.inorder();
			}
		}

		public int maxDepth() {
			if (left == null)
				return 0;
			if (right == null)
				return 0;
			else {
				int ll = left.maxDepth();
				int rr = right.maxDepth();
				if (ll > rr)
					return (ll + 1);
				else
					return (rr + 1);
			}
		}

		public int countNodes() {
			if (left == null)
				return 1;
			if (right == null)
				return 1;
			else {
				return left.countNodes() + right.countNodes() + 1;
			}
		}

		public void preorder() {
			System.out.print(data + " ");
			if (left != null) {
				left.inorder();
			}

			if (right != null) {
				right.inorder();
			}

		}

		public void postorder() {
			if (left != null) {
				left.inorder();
			}

			if (right != null) {
				right.inorder();
			}
			System.out.print(data + " ");

		}

		public void levelorder(Node node) {
			LinkedList<Node> ll = new LinkedList<Node>();
			ll.add(node);
			getorder(ll);

		}

		public void getorder(LinkedList<Node> ll) {
			while (!ll.isEmpty()) {
				Node node = ll.poll();
				System.out.print(node.data + " ");
				if (node.left != null)
					ll.add(node.left);
				if (node.right != null)
					ll.add(node.right);
			}
		}
	}

	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;
		}
	}

	static class Pair {
		int first, second;

		public Pair(int first, int second) {
			this.first = first;
			this.second = second;
		}

	}

	static class Pair2 {
		int first;
		Pair second;

		public Pair2(int first, Pair second) {
			this.first = first;
			this.second = second;
		}

	}

	static class LongPair {
		long first, second;

		public LongPair(long first, long second) {
			this.first = first;
			this.second = second;
		}

	}

	static class OutputWriter {
		private final PrintWriter writer;

		public OutputWriter(OutputStream outputStream) {
			writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
		}

		public OutputWriter(Writer writer) {
			this.writer = new PrintWriter(writer);
		}

		public void print(Object... objects) {
			for (int i = 0; i < objects.length; i++) {
				if (i != 0)
					writer.print(' ');
				writer.print(objects[i]);
			}
		}

		public void printLine(Object... objects) {
			print(objects);
			writer.println();
		}

		public void close() {
			writer.close();
		}

		public void flush() {
			writer.flush();
		}

	}

	private static final Scanner sc = new Scanner(System.in);
	private static final FastReader fs = new FastReader();
	private static final OutputWriter op = new OutputWriter(System.out);

	static int[] getintarray(int n) {
		int ar[] = new int[n];
		for (int i = 0; i < n; i++) {
			ar[i] = fs.nextInt();
		}
		return ar;
	}

	static long[] getlongarray(int n) {
		long ar[] = new long[n];
		for (int i = 0; i < n; i++) {
			ar[i] = fs.nextLong();
		}
		return ar;
	}

	static int[][] get2darray(int n, int m) {
		int ar[][] = new int[n][m];
		for (int i = 0; i < n; i++) {
			for (int j = 0; j < m; j++) {
				ar[i][j] = fs.nextInt();
			}
		}
		return ar;
	}

	static Pair[] getpairarray(int n) {
		Pair ar[] = new Pair[n];
		for (int i = 0; i < n; i++) {
			ar[i] = new Pair(fs.nextInt(), fs.nextInt());
		}
		return ar;
	}

	static void printarray(int ar[]) {
		for (int i : ar) {
			op.print(i + " ");
		}
		op.flush();
	}

	static int fact(int n) {
		int fact = 1;
		for (int i = 2; i <= n; i++) {
			fact *= i;
		}
		return fact;
	}

//	

	// function to find largest prime factor

}