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.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;
import java.util.StringTokenizer;

public class Main {
    public static void main(final String[] args) {
        final FastScanner scanner = new FastScanner(System.in);
        final int h = scanner.nextInt();
        final int w = scanner.nextInt();
        final int[][] table = new int[h][w];

        for (int i = 0; i < h; i++) {
            for (int j = 0; j < w; j++) {
                table[i][j] = scanner.nextInt();
            }
        }

        final List<String> answers = new ArrayList<>();

        for (int i = 0; i < h; i++) {
            if (i % 2 == 0) {
                for (int j = 0; j < w; j++) {
                    if (i == h - 1 && j == w - 1) {
                        break;
                    }

                    if (table[i][j] % 2 == 0) {
                        continue;
                    }

                    if (j == w - 1) {
                        table[i][j]--;
                        table[i + 1][j]++;
                        answers.add((i + 1) + " " + (j + 1) + " " + (i + 2) + " " + (j + 1));
                        continue;
                    }

                    table[i][j]--;
                    table[i][j + 1]++;
                    answers.add((i + 1) + " " + (j + 1) + " " + (i + 1) + " " + (j + 2));
                }
            } else {
                for (int j = w - 1; j >= 0; j--) {
                    if (i == h - 1 && j == 0) {
                        break;
                    }

                    if (table[i][j] % 2 == 0) {
                        continue;
                    }

                    if (j == 0) {
                        table[i][j]--;
                        table[i + 1][j]++;
                        answers.add((i + 1) + " " + (j + 1) + " " + (i + 2) + " " + (j + 1));
                        continue;
                    }

                    table[i][j]--;
                    table[i][j - 1]++;
                    answers.add((i + 1) + " " + (j + 1) + " " + (i + 1) + " " + j);
                }
            }
        }

        System.out.println(answers.size());
        for (String answer : answers) {
            System.out.println(answer);
        }
    }

    static class FastScanner {
        private final BufferedReader reader;
        private StringTokenizer tokenizer;

        FastScanner(final InputStream in) {
            reader = new BufferedReader(new InputStreamReader(in));
            tokenizer = null;
        }

        String next() {
            if (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }

        int nextInt() {
            return Integer.parseInt(next());
        }
    }
}