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.*;

class Main{
	

	public static ArrayList<Log> logs = new ArrayList<>();


	public static void main(String args[]){

		Scanner sc = new Scanner(System.in);
		
		int H = sc.nextInt();
		int W = sc.nextInt();

		boolean map[][] = new boolean[H][W];

		int rem = 0;

		for(int h=0;h<H;h++){
			for(int w=0;w<W;w++){
				int c = sc.nextInt();
				if(c%2==0) map[h][w] = true;
				else{
				 map[h][w] = false;
				 rem++;
				}
			}
		}

		int rem_x = -1;
		int rem_y = -1;
		int p_x = -1;
		int p_y = -1;

		for(int h=0;h<H;h++){
			if(rem < 2) break;
			if(h%2==0){
				for(int w=0;w<W;w++){

					if(!(rem_x == -1 && rem_y == -1)){
						logs.add(new Log(p_y,p_x,h,w));
					}
					if(!map[h][w]){
						if(rem_x == -1 && rem_y == -1){
							rem_x = w;
							rem_y = h;
							p_x = rem_x;
							p_y = rem_y;
						}else{
							map[rem_y][rem_x] = false;
							map[h][w] = false;
							rem -= 2;
							rem_x = -1;
							rem_y = -1;
						}
					}
					p_x = w;
					p_y = h;
				}

			}else{
				for(int w=W-1;w>=0;w--){

					if(!(rem_x == -1 && rem_y == -1)){
						logs.add(new Log(p_y,p_x,h,w));
					}
					if(!map[h][w]){
						if(rem_x == -1 && rem_y == -1){
							rem_x = w;
							rem_y = h;
							p_x = rem_x;
							p_y = rem_y;
						}else{
							map[rem_y][rem_x] = false;
							map[h][w] = false;
							rem -= 2;
							rem_x = -1;
							rem_y = -1;
						}
					}
					p_x = w;
					p_y = h;
				}

			}
		}

		System.out.println(logs.size());
		for(int n=0;n<logs.size();n++){
			System.out.println(logs.get(n).y+" "+logs.get(n).x+" "+logs.get(n)._y+" "+logs.get(n)._x);
		}


	}

	private static class Log{
		int y,x,_y,_x;
		Log(int y,int x,int _y,int _x){
			this.y = y+1;
			this.x = x+1;
			this._y = _y+1;
			this._x = _x+1;
		}
	}
}