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.Scanner;

public class Main {
  public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);

    int H = scanner.nextInt();
    int W = scanner.nextInt();
    int[][] a = new int[H][W];
    for (int i = 0; i < H; i++) for (int j = 0; j < W; j++) a[i][j] = scanner.nextInt();

    StringBuilder sb = new StringBuilder();
    int cnt = 0;
    for (int n = 0; n < H * W - 1; n++) {
      int ci = ntoi(n, H, W);
      int cj = ntoj(n, H, W);
      int ni = ntoi(n + 1, H ,W);
      int nj = ntoj(n + 1, H, W);
      if (a[ci][cj] % 2 != 0) {
        a[ni][nj]++;
        cnt++;
        sb.append(String.format("%d %d %d %d\n", ci + 1, cj + 1, ni + 1, nj + 1));
      }
    }
    System.out.println(cnt);
    if (sb.length() > 0) System.out.print(sb.toString());
  }

  private static int ntoi(int n, int H, int W) {
    return n / W;
  }

  private static int ntoj(int n, int H, int W) {
    int i = n / W;
    if (i % 2 == 0) {
      return n % W;
    }
    int j = n % W;
    j = W - j - 1;
    return j;
  }
}