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.*;

public class Main {

  public static class Pair {
    int y;
    int x;
    int a;

    public Pair(int y, int x, int a) {
      this.y = y;
      this.x = x;
      this.a = a;
    }
  }

  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 i = 0; i < H; i++) {
      for (int j = 0; j < W; j++) {
        a[i][j] = sc.nextInt();
      }
    }
    Pair[] root = new Pair[H * W];
    int count = 0;
    int sy = 0;
    int sx = 0;
    boolean left = true;
    while (count < H * W) {
      if (W <= sx) {
        sx--;
        sy++;
        left = false;
      } else if (sx < 0) {
        sx++;
        sy++;
        left = true;
      }
      root[count] = new Pair(sy, sx, a[sy][sx]);
      if (left) {
        sx++;
      } else {
        sx--;
      }
      count++;
    }
    boolean[] ans = new boolean[H * W];
    int anscount = 0;
    Arrays.fill(ans, false);
    for (int i = 0; i < H * W - 1; i++) {
      if (root[i].a % 2 == 1) {
        root[i + 1].a++;
        ans[i] = true;
        anscount++;
      }
    }
    System.out.println(anscount);
    for (int i = 0; i < H * W - 1; i++) {
      if (ans[i]) {
        System.out
            .println((root[i].y + 1) + " " + (root[i].x + 1) + " " + (root[i + 1].y + 1) + " " + (root[i + 1].x + 1));
      }
    }
  }
}