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 = sc.nextInt();
        int W = sc.nextInt();
        int[][] a = new int[H][W];
        
        for(int i = 0; i < H; i++){
            for(int j = 0; j < W; j++){
                a[i][j] = sc.nextInt();
            }
        }
        sc.close();
        ArrayList<ArrayList<Integer>> list = new ArrayList<ArrayList<Integer>>();
        int i = 0, j = 0;
        int cnt = 0;
        while(cnt < H*W-1){
            if(a[i][j]%2 == 1){
                ArrayList<Integer> list1 = new ArrayList<>();
                list1.add(i+1);
                list1.add(j+1);
                if(i%2 == 0){
                    if(j != W-1){
                        a[i][j+1]++;
                        j++;
                    } else {
                        a[i+1][j]++;
                        i++;
                    }
                } else {
                    if(j != 0){
                        a[i][j-1]++;
                        j--;
                    } else {
                        a[i+1][j]++;
                        i++;
                    }
                }
                list1.add(i+1);
                list1.add(j+1);
                list.add(list1);
            } else {
                if(i%2 == 0){
                    if(j != W-1){
                        j++;
                    } else {
                        i++;
                    }
                } else {
                    if(j != 0){
                        j--;
                    } else {
                        i++;
                    }
                }
            }
            cnt++;
        }
        System.out.println(list.size());
        for(int k = 0; k < list.size(); k++){
            System.out.println(list.get(k).get(0) + " " + list.get(k).get(1) + " " + 
            list.get(k).get(2) + " " + list.get(k).get(3));
        }
    }
}