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 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();
      }
    }

    ArrayList<int[]> list = new ArrayList<int[]>();
    
    for(int i = 0; i < h; i++) {
        if(i % 2 == 0) {
          for(int j = 0; j < w; j++) {
            if((i + j) < h + w - 2) {
              if(a[i][j] % 2 == 1) {
                int[] s = {i, j};
                int[] t = new int[2];
                list.add(s);
                if(j < w - 1) {
                  a[i][j + 1]++;
                  t[0] = i;
                  t[1] = j + 1;
                } else {
                  a[i + 1][j]++;
                  t[0] = i + 1;
                  t[1] = j;
                }
                list.add(t);
              }
            }
          }
        }   else {
            for(int j = w - 1; j >= 0; j--) {
              if((!((i == h - 1) && (j == 0)))) {
                if(a[i][j] % 2 == 1) {
                  int[] s = {i, j};
                  int[] t = new int[2];
                  list.add(s);
                  if(j > 0) {
                    a[i][j - 1]++;
                    t[0] = i;
                    t[1] = j - 1;
                  } else {
                    a[i + 1][j]++;
                    t[0] = i + 1;
                    t[1] = j;
                  }
                  list.add(t);
                }
              }
            }
          }
        }

    int n = 0;
    int p = 1;
    for(int i = 0; i < list.size() - 1; i++) {
      int[] s = list.get(i);
      int[] t = list.get(i + 1);
      if(((s[0] != t[0]) || (s[1] != t[1])) && (p == 1)) {
        p = 0;
        n++;
      } else {
        p = 1;
      }
    }  
    System.out.println(n);

    p = 1;
    for(int i = 0; i < list.size() - 1; i++) {
      int[] s = list.get(i);
      int[] t = list.get(i + 1);
      if(((s[0] != t[0]) || (s[1] != t[1])) && (p == 1)) {
        String str = "";
        str += (s[0] + 1);
        str += (" ");
        str += (s[1] + 1);
        str += (" ");
        str += (t[0] + 1);
        str += (" ");
        str += (t[1] + 1);
        System.out.println(str);
        p = 0;
      } else {
        p = 1;
      }
    }
  }
}