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.InputStreamReader;

public class Main {

  public static void main(String[] args) {
    
    new Main().run();
  }

  public void run() {
    
    try(BufferedReader in = new BufferedReader(new InputStreamReader(System.in))) {

      String[] lines = in.readLine().split(" ");
      int h = Integer.parseInt(lines[0]);
      int w = Integer.parseInt(lines[1]);

      char[][] table = new char[h][w];
      String line;
      for(int i=0; i<h; i++) {
        line = in.readLine();
        for(int j=0,k=0; j<w; j++, k+=2) {
          table[i][j] = (char)Character.getNumericValue(line.charAt(k));
        }
      }

      int n = 0;
      StringBuilder buf = new StringBuilder();
      for(int i=0; i<h-1; i++) {
        for(int j=0; j<w; j++) {
          if((table[i][j] & 1) == 1) {
            table[i][j]--;
            table[i+1][j]++;
            n++;
            buf.append(i+1).append(" ").append(j+1).append(" ")
               .append(i+2).append(" ").append(j+1).append("\n");
          }
        }
      }

      for(int j=0; j<w-1; j++) {
        if((table[h-1][j] & 1) == 1) {
          table[h-1][j]--;
          table[h-1][j+1]++;
          n++;
          buf.append(h).append(" ").append(j+1).append(" ")
             .append(h).append(" ").append(j+2).append("\n");
        }
      }
      StringBuilder ans = new StringBuilder();
      ans.append(n).append("\n").append(buf);

      System.out.print(ans);
    }
    catch(IOException e) {
      System.err.println(e);
    }
  }
}