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.Arrays;
import java.util.Scanner;
public class Main {
public static void main(String[] args){
        Scanner sc = new Scanner(System.in);

        int h = sc.nextInt();
        int w = sc.nextInt();
        int a[][] = new int[h][w];
        int sum = 0;


        for(int i=0;i<h;i++) {
        	for(int j=0;j<w;j++) {
        		a[i][j] = sc.nextInt();
        		sum = a[i][j];
        	}
        }
        int z = h*w;
        String t[] = new String[z];
        Arrays.fill(t, "");

        int r = 0;
        int k=0;

        for(int i = 0;i<h;i++) {
        	if(i%2 == 0) {
        		for(int j=0;j<w-1;j++) {
        			if((a[i][j] + r)%2 == 1) {
        				t[k] = ((i+1) + " " + (j+1) + " " + (i+1) + " " + (j+2));
        				r = 1;
        				k= k+1;
        			}else {
        				r = 0;
        			}
        		}
        		if(i != h-1 && (a[i][w-1]+r)%2 == 1) {
        			t[k] = ((i+1) + " " + w + " " + (i+2) + " " + w);
        			r = 1;
    				k= k+1;
        		}else {
        			r = 0;
        		}
        	}else {

        		for(int j=w-1;j>0;j--) {
        			if((a[i][j] + r)%2 == 1) {
        				t[k] = ((i+1) + " " + (j+1) + " " + (i+1) + " " + j);
        				r = 1;
        				k= k+1;
        			}else {
        				r = 0;
        			}
        		}
        		if(i != h-1 && (a[i][0]+r)%2 == 1) {
        			t[k] = ((i+1) + " " + 1 + " " + (i+2) + " " + 1);
        			r = 1;
    				k= k+1;
        		}else {
        			r = 0;
        		}
        	}
        }
    	System.out.println(k);
    	for(int i=0;i<k;i++) {
    		System.out.println(t[i]);
    	}

    }

}