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.*;
class Main
{
    public static void main (String[] args)
    {
        Scanner sc = new Scanner(System.in);
        int h = sc.nextInt(), 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() % 2;
            }
        }
        int[] b = new int[h*w];
        int[] c = new int[h*w];
        int[] d = new int[h*w];
        int[] e = new int[h*w];
        int[] y = new int[h*w];
        int[] x = new int[h*w];
        int cnt = -1;
        for(int i = 0; i < h; i++){
            if(i % 2 == 0){
                for(int j = 0; j < w; j++){
                    ++cnt;
                    y[cnt] = i;
                    x[cnt] = j;  
                }
            }else{
                for(int j = w - 1; j >= 0; j--){
                    ++cnt;
                    y[cnt] = i;
                    x[cnt] = j;
                } 
            }
        }
        int ans = -1;
        for(int i = 0; i < cnt; i++){
            if(a[y[i]][x[i]] % 2 == 1){
                ans++;
                b[ans] = y[i] + 1;
                c[ans] = x[i] + 1;
                d[ans] = y[i+1] + 1;
                e[ans] = x[i+1] + 1;
                a[y[i+1]][x[i+1]]++;
            }
        }
        System.out.println(++ans);
        for(int i = 0; i < ans; i++){
            System.out.println(b[i] + " " + c[i] + " " + d[i] + " "  + e[i]);
        }
    }
}