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 scanner = new Scanner(System.in);
        int H = scanner.nextInt();
        int W = scanner.nextInt();
        int[][] a = new int[H][W];
        for (int i = 0; i < H; i++) {
            for (int j = 0; j < W; j++) {
                a[i][j] = scanner.nextInt()%2;
            }
        }
        ArrayList<int[]> move = new ArrayList<>();
        for (int i = 0; i < H; i++) {
            for (int j = 0; j < W-1; j++) {
                if(a[i][j]==1){
                    a[i][j+1] = (a[i][j+1] + 1)%2;
                    move.add(new int[]{i,j,i,j+1});
                }
            }
        }
        for (int i = 0; i < H-1; i++) {
            if(a[i][W-1] == 1){
                a[i+1][W-1] = (a[i+1][W-1]+1)%2;
                move.add(new int[]{i,W-1, i+1,W-1});
            }
        }
        System.out.println(move.size());
        for (int i = 0; i < move.size(); i++) {
            int[] mv = move.get(i);
            System.out.println(
                String.format("%d %d %d %d",
                    mv[0] +1,
                    mv[1] +1,
                    mv[2] +1,
                    mv[3] +1));
        }
    }
}