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 CPP):

Solution:
#include<bits/stdc++.h>
using namespace std;

const int maxN=505;
const int inf=2147483647;

class Outp
{
public:
	int x1,y1,x2,y2;
};

int n,m;
int Mt[maxN][maxN];
int scnt=0;
Outp O[maxN*maxN];

int main(){
	cin>>n>>m;
	for (int i=1;i<=n;i++) for (int j=1;j<=m;j++) cin>>Mt[i][j];
	for (int i=1;i<=n;i++)
		if (i&1){
			for (int j=1;j<m;j++)
				if (Mt[i][j]&1)
					O[++scnt]=((Outp){i,j,i,j+1}),Mt[i][j+1]++;
			if ((Mt[i][m]&1)&&(i!=n)) O[++scnt]=((Outp){i,m,i+1,m}),Mt[i+1][m]++;
		}
		else{
			for (int j=m;j>1;j--)
				if (Mt[i][j]&1)
					O[++scnt]=((Outp){i,j,i,j-1}),Mt[i][j-1]++;
			if ((Mt[i][1]&1)&&(i!=n)) O[++scnt]=((Outp){i,1,i+1,1}),Mt[i+1][1]++;
		}
	cout<<scnt<<endl;
	for (int i=1;i<=scnt;i++) cout<<O[i].x1<<" "<<O[i].y1<<" "<<O[i].x2<<" "<<O[i].y2<<endl;
	return 0;
}