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[][] d = new int[h + 1][w + 1];
        for (int i = 1; i <= h; i++) {
            for (int j = 1; j <= w; j++) {
                d[i][j] = sc.nextInt();
            }
        }

        List<String> ans = new ArrayList<>();
        for (int i = 1; i <= h; i++) {
            for (int j = 1; j <= w; j++) {
                if (i == h && j == w) {
                    continue;
                }
                int x = i;
                int y = 0;
                if (i % 2 == 1) {
                    y = j;
                } else {
                    y = w - j + 1;
                }
                if (d[x][y] % 2 == 0) {
                    continue;
                }
                StringBuilder sb = new StringBuilder();
                if ((y == w && x % 2 == 1)) {
                    sb.append(x);
                    sb.append(" ");
                    sb.append(y);
                    sb.append(" ");
                    sb.append(x + 1);
                    sb.append(" ");
                    sb.append(y);
                    ans.add(sb.toString());
                    d[x + 1][y]++;
                } else if ((y == 1 && x % 2 == 0)) {
                    sb.append(x);
                    sb.append(" ");
                    sb.append(y);
                    sb.append(" ");
                    sb.append(x + 1);
                    sb.append(" ");
                    sb.append(y);
                    ans.add(sb.toString());
                    d[x + 1][y]++;
                } else if ((x % 2 == 1)) {
                    sb.append(x);
                    sb.append(" ");
                    sb.append(y);
                    sb.append(" ");
                    sb.append(x);
                    sb.append(" ");
                    sb.append(y + 1);
                    ans.add(sb.toString());
                    d[x][y + 1]++;
                } else if ((x % 2 == 0)) {
                    sb.append(x);
                    sb.append(" ");
                    sb.append(y);
                    sb.append(" ");
                    sb.append(x);
                    sb.append(" ");
                    sb.append(y - 1);
                    ans.add(sb.toString());
                    d[x][y - 1]++;
                }
            }
        }

        System.out.println(ans.size());
        for (String s : ans) {
            System.out.println(s);
        }
    }
}