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.*;

public class Main {
	public static void main(String args[]) {
		Scanner sc = new Scanner(System.in);
		int H = Integer.parseInt(sc.next());
		int W = Integer.parseInt(sc.next());
		int a[][] = new int[H][W];
		for(int i = 0; i < H; i++) {
			for(int j = 0; j < W; j++) {
				a[i][j] = Integer.parseInt(sc.next()) % 2;
			}
		}
		Queue<Integer> ans_y1 = new ArrayDeque<Integer>();
		Queue<Integer> ans_x1 = new ArrayDeque<Integer>();
		Queue<Integer> ans_y2 = new ArrayDeque<Integer>();
		Queue<Integer> ans_x2 = new ArrayDeque<Integer>();
		for(int h = 0; h < H; h++) {
			if(h % 2 == 0) {
				for(int w = 0; w < W; w++) {
					if(a[h][w] == 1) {
						if(w == W - 1) {
							if(h != H - 1) {
								a[h][w]--;
								ans_y1.add(h);
								ans_x1.add(w);
								a[h + 1][w]++;
								ans_y2.add(h + 1);
								ans_x2.add(w);
							}
						} else {
							a[h][w]--;
							ans_y1.add(h);
							ans_x1.add(w);
							a[h][w + 1]++;
							ans_y2.add(h);
							ans_x2.add(w + 1);
						}

					}
				}
			} else {
				for(int w = W - 1; w >= 0; w--) {
					if(a[h][w] == 1) {
						if(w == 0) {
							if(h != H - 1) {
								a[h][w]--;
								ans_y1.add(h);
								ans_x1.add(w);
								a[h + 1][w]++;
								ans_y2.add(h + 1);
								ans_x2.add(w);
							}
						} else {
							a[h][w]--;
							ans_y1.add(h);
							ans_x1.add(w);
							a[h][w - 1]++;
							ans_y2.add(h);
							ans_x2.add(w - 1);
						}
					}
				}
			}
		}
		int ans_cnt = ans_y1.size();
		System.out.println(ans_cnt);
		for(int i = 0; i < ans_cnt; i++) {
			System.out.print(ans_y1.poll() + 1 + " ");
			System.out.print(ans_x1.poll() + 1 + " ");
			System.out.print(ans_y2.poll() + 1 + " ");
			System.out.println(ans_x2.poll() + 1);
		}
	}
}