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.List;
import java.util.Scanner;

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 r = 0; r < H; ++r) {
            for (int c = 0; c < W; ++c) {
                a[r][c] = sc.nextInt();
            }
        }

        System.out.println(solve(a));

        sc.close();
    }

    static String solve(int[][] a) {
        int H = a.length;
        int W = a[0].length;

        List<String> operations = new ArrayList<>();
        int r = 0;
        int c = 0;
        int offsetC = 1;
        while (r != H) {
            int nextR = r;
            int nextC = c + offsetC;
            if (nextC == -1 || nextC == W) {
                ++nextR;
                offsetC *= -1;
                nextC += offsetC;
            }

            if (a[r][c] % 2 != 0) {
                --a[r][c];

                if (nextR != H) {
                    ++a[nextR][nextC];

                    operations.add(String.format("%d %d %d %d", r + 1, c + 1, nextR + 1, nextC + 1));
                }
            }

            r = nextR;
            c = nextC;
        }

        return String.format("%d\n%s", operations.size(), String.join("\n", operations));
    }
}