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.io.BufferedReader;
import java.io.InputStreamReader;
import java.lang.reflect.Array;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Main main = new Main();
        main.solve();
    }
    public void solve() {
        Scanner scan = new Scanner(new BufferedReader(new InputStreamReader(System.in)));
        int H = scan.nextInt();
        int W = scan.nextInt();
        int[][] a = new int[H][W];
        for (int i = 0; i < H; i++) {
            for (int j = 0; j < W; j++) {
                a[i][j] = scan.nextInt();
            }
        }
        int move_count = 0;
        List<String> moves = new ArrayList<>();
        for (int i = 0; i < H; i++) {
            int start = i % 2 == 0 ? 0 : W - 1;
            int increment = i % 2 == 0 ? 1 : -1;
            for (int j = start; j < W && 0 <= j; j = j + increment) {
                if (a[i][j] % 2 == 0) {
                    continue;
                }
                if (i % 2 == 0 && j + 1 < W) {
                    a[i][j] -= 1;
                    a[i][j+1] += 1;
                    move_count += 1;
                    moves.add(String.format("%d %d %d %d", (i+1), (j+1), (i+1), (j+2)));
                    continue;
                }
                if (i % 2 == 1 && 0 <= j - 1) {
                    a[i][j] -= 1;
                    a[i][j-1] += 1;
                    move_count += 1;
                    moves.add(String.format("%d %d %d %d", (i+1), (j+1), (i+1), (j)));
                    continue;
                }
                if (i % 2 == 0 && j == W - 1 && i + 1 < H) {
                    a[i][j] -= 1;
                    a[i+1][j] += 1;
                    move_count += 1;
                    moves.add(String.format("%d %d %d %d", (i+1), (j+1), (i+2), (j+1)));
                    continue;
                }
                if (i % 2 == 1 && j == 0 && i + 1 < H) {
                    a[i][j] -= 1;
                    a[i+1][j] += 1;
                    move_count += 1;
                    moves.add(String.format("%d %d %d %d", (i+1), (j+1), (i+2), (j+1)));
                    continue;
                }
            }
        }
        System.out.println(move_count);
        for (int i = 0; i < move_count; i++) {
            System.out.println(moves.get(i));
        }
    }
}