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:
/*Lucky_Glass*/
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<vector>
using namespace std;
const int N=500;
struct ANS{
	int a,b,c,d;
	ANS(int x,int y,int z,int w):a(x),b(y),c(z),d(w){};
};
vector<ANS> ans;
int r,c;
int val[N+5][N+5];
bool vis[N+5][N+5];
int main(){
	scanf("%d%d",&r,&c);
	for(int i=0;i<r;i++)
		for(int j=0;j<c;j++)
			scanf("%d",&val[i][j]),
			val[i][j]&=1;
	for(int i=0;i<r;i++)
		for(int j=0;j<c-1;j++)
			if(val[i][j])
				val[i][j+1]^=val[i][j],
				ans.push_back(ANS(i+1,j+1,i+1,j+2));
	for(int i=0;i<r-1;i++)
		if(val[i][c-1])
			val[i+1][c-1]^=val[i][c-1],
			ans.push_back(ANS(i+1,c,i+2,c));
	printf("%d\n",ans.size());
	for(int i=0;i<ans.size();i++)
		printf("%d %d %d %d\n",ans[i].a,ans[i].b,ans[i].c,ans[i].d);
	return 0;
}