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.ArrayList;
import java.util.Scanner;

class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int h = sc.nextInt();
        int w = sc.nextInt();
        int map[][] = new int[h][w];
        ArrayList<Operate> op = new ArrayList<>();
        for (int i = 0; i < h; i++) {
            for (int j = 0; j < w; j++) {
                map[i][j] = sc.nextInt();
            }
        }
        for (int i = 0; i < h; i++) {
            if (i % 2 == 0) {
                // 偶数行目 左 => 右
                for (int j = 0; j < w - 1; j++) {
                    if (map[i][j] % 2 == 0) {
                        continue;
                    } else {
                        // [[i][j]はあまりがある
                        op.add(new Operate(i, j, i, j + 1));
                        map[i][j + 1]++;
                    }
                }
                // 最下段でない
                if (i != h - 1) {
                    if (map[i][w - 1] % 2 == 0) {
                        continue;
                    } else {
                        // [[i][j]はあまりがある
                        op.add(new Operate(i, w - 1, i + 1, w - 1));
                        map[i + 1][w - 1]++;
                    }
                }
            } else {
                for (int j = w - 1; j > 0; j--) {
                    if (map[i][j] % 2 == 0) {
                        continue;
                    } else {
                        // [[i][j]はあまりがある
                        op.add(new Operate(i, j, i, j - 1));
                        map[i][j - 1]++;
                    }
                }
                // 最下段でない
                if (i != h - 1) {
                    if (map[i][0] % 2 == 0) {
                        continue;
                    } else {
                        // [[i][j]はあまりがある
                        op.add(new Operate(i, 0, i + 1, 0));
                        map[i + 1][0]++;
                    }
                }
            }
        }
        System.out.println(op.size());
        for (Operate operate : op) {
            operate.show();
        }

        sc.close();
    }
}

class Operate {

    int i, j, ni, nj;

    Operate(int i, int j, int ni, int nj) {
        this.i = i + 1;
        this.j = j + 1;
        this.ni = ni + 1;
        this.nj = nj + 1;
    }

    public void show() {
        System.out.println(i + " " + j + " " + ni + " " + nj);
    }
}