Problem: There is a grid of square cells with H horizontal rows and W vertical columns. The cell at the i-th row and the j-th column will be denoted as Cell (i, j).

In Cell (i, j), a_{ij} coins are placed.

You can perform the following operation any number of times:

Operation: Choose a cell that was not chosen before and contains one or more coins, then move one of those coins to a vertically or horizontally adjacent cell.

Maximize the number of cells containing an even number of coins.

Constraints

* All values in input are integers.
* 1 \leq H, W \leq 500
* 0 \leq a_{ij} \leq 9

Input

Input is given from Standard Input in the following format:


H W
a_{11} a_{12} ... a_{1W}
a_{21} a_{22} ... a_{2W}
:
a_{H1} a_{H2} ... a_{HW}


Output

Print a sequence of operations that maximizes the number of cells containing an even number of coins, in the following format:


N
y_1 x_1 y_1' x_1'
y_2 x_2 y_2' x_2'
:
y_N x_N y_N' x_N'


That is, in the first line, print an integer N between 0 and H \times W (inclusive), representing the number of operations.

In the (i+1)-th line (1 \leq i \leq N), print four integers y_i, x_i, y_i' and x_i' (1 \leq y_i, y_i' \leq H and 1 \leq x_i, x_i' \leq W), representing the i-th operation. These four integers represents the operation of moving one of the coins placed in Cell (y_i, x_i) to a vertically or horizontally adjacent cell, (y_i', x_i').

Note that if the specified operation violates the specification in the problem statement or the output format is invalid, it will result in Wrong Answer.

Examples

Input

2 3
1 2 3
0 1 1


Output

3
2 2 2 3
1 1 1 2
1 3 1 2


Input

3 2
1 0
2 1
1 0


Output

3
1 1 1 2
1 2 2 2
3 1 3 2


Input

1 5
9 9 9 9 9


Output

2
1 1 1 2
1 3 1 4

Solution (in JAVA):

Solution:
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
import java.util.stream.IntStream;

/**
 * 解説通りに作成したソースコード
 */
public class Main {

	public static void main(String[] args) {
		try (Scanner scanner = new Scanner(System.in)) {
			int h = scanner.nextInt(), w = scanner.nextInt();
			int[][] a = new int[h][w];
			IntStream.range(0, h).forEach(i -> IntStream.range(0, w).forEach(j -> a[i][j] = scanner.nextInt()));
			List<Move> moves = new ArrayList<>(), currentMoves = new ArrayList<>();
			int prevX = -1, prevY = -1;
			for (int i = 0; i < h; i++) {
				for (int j = 0; j < w; j++) {
					int x = i, y = (0 == (x & 1)) ? j : w - 1 - j;
					if ((prevX >= 0) && (prevY >= 0)) {
						currentMoves.add(new Move(prevX, prevY, x, y));
						if (0 != (a[x][y] & 1)) {
							prevX = -1;
							prevY = -1;
							moves.addAll(currentMoves);
							currentMoves.clear();
						} else {
							prevX = x;
							prevY = y;
						}
					} else if (0 != (a[x][y] & 1)) {
						prevX = x;
						prevY = y;
					}
				}
			}
			System.out.println(moves.size());
			moves.stream().forEach(System.out::println);
		}
	}

	/**
	 * 移動方法を表すクラス
	 */
	private static class Move {
		int x1, y1, x2, y2;

		Move(int x1, int y1, int x2, int y2) {
			super();
			this.x1 = x1;
			this.y1 = y1;
			this.x2 = x2;
			this.y2 = y2;
		}

		@Override
		public String toString() {
			StringBuilder sb = new StringBuilder();
			sb.append(x1 + 1).append(" ");
			sb.append(y1 + 1).append(" ");
			sb.append(x2 + 1).append(" ");
			sb.append(y2 + 1);
			return sb.toString();
		}
	}
}