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.*;
import java.util.ArrayList;
import java.util.Collections;

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];
        ArrayList<Integer> list = new ArrayList<Integer>();
        ArrayList<Integer> listh = new ArrayList<Integer>();
        ArrayList<Integer> listw = new ArrayList<Integer>();
        if(H==1 && W==1){
            System.out.println(0);
            return;
        }

        for(int i=0; i<H; i++){
            for(int j=0; j<W; j++){
                a[i][j] = sc.nextInt();
            }
            if(i%2==0){
                for(int j=0; j<W; j++){
                    list.add(a[i][j]);
                    listh.add(i);
                    listw.add(j);
                }
            }
            else{
                for(int j=W-1; j>=0; j--){
                    list.add(a[i][j]);
                    listh.add(i);
                    listw.add(j);
                }
            }
        }
        int[] x = new int[H * W];
        int[] A = new int[H * W];
        int y = 0;
        if(list.get(0)%2==1){
            x[y] = 0;
            A[0] = list.get(0) - 1;
            A[1] = 1;
            y++;
        }
        for(int i=1; i<list.size(); i++){
            A[i] += list.get(i);
            if(i==list.size()-1){
                break;
            }
            if(A[i]%2==1){
                A[i] -= 1;
                A[i + 1] = 1;
                x[y] = i;
                y++;
            }
        }
        System.out.println(y);
        for(int i=0; i<y; i++){
            int b1 = listh.get(x[i]) + 1;
            int b2 = listw.get(x[i]) + 1;
            int b3 = listh.get(x[i] + 1) + 1;
            int b4 = listw.get(x[i] + 1) + 1;
            System.out.println(b1 + " " + b2 + " " + b3 + " " + b4);
        }
    }
}