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.InputStreamReader;
import java.util.ArrayList;

public class Main{
	public static void main(String[] args)throws Exception{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String[] strs = br.readLine().split(" ");
		int h = Integer.parseInt(strs[0]);
		int w = Integer.parseInt(strs[1]);
		boolean[][] map = new boolean[h][w];
		for(int i = 0 ; i < h ; i++){
			strs = br.readLine().split(" ");
			for(int j = 0 ; j < w ; j++){
				map[i][j] = Integer.parseInt(strs[j]) % 2  == 1;
			}
		}
		
		ArrayList<String> result = new ArrayList<String>();
		
		int j1 = 0;
		L1:for(int i = 0 ; i < h ; i++){
			while(!map[i][j1]){
				j1++;
				if(j1 >= w){
					j1 = 0;
					continue L1;
				}
			}
			int j2 = j1 +1;
			if(j2 >= w){
				if(i+1 < h){
					map[i][j1] = false;
					map[i+1][j1] = !map[i+1][j1];
					result.add((i+1)  + " " + (j1+1) + " " + (i+1+1) + " " + (j1+1));
				}
				j1 = 0;
				continue L1;
			}
			while(!map[i][j2]){
				j2++;
				if(j2 >= w){
					if(i+1 < h){
						map[i][j1] = false;
						map[i+1][j1] = !map[i+1][j1];
						result.add((i+1)  + " " + (j1+1) + " " + (i+1+1) + " " + (j1+1));
					}
					j1 = 0;
					continue L1;
				}
			}
			
			for(int m = j1 ; m < j2 ; m++){
				result.add((i+1)  + " " + (m+1) + " " + (i+1) + " " + (m+1+1));
			}
			
			map[i][j1] = false;
			map[i][j2] = false;
			j1 = j2;
			i--;
			continue L1;
		}
		/*
		for(int i = 0 ; i < h ; i++){
			for(int j = 0 ; j < w ; j++){
				System.out.print(map[i][j]?"x":"o");
			}
			System.out.println();
		}*/
		
		System.out.println(result.size());
		for(String s:result){
			System.out.println(s);
		}
	}
}