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<cstdio>
const int maxn=510;
int h,v;
int a[maxn][maxn];
int nm;
struct Move {
	int a,b,c,d;
}mv[maxn*maxn];
int main() {
	scanf("%d%d",&h,&v);
	for(register int i=1;i<=h;++i)for(register int j=1;j<=v;++j)scanf("%d",&a[i][j]);
	for(register int i=1;i<=h;++i) {
		if(i&1) {
			for(register int j=1;j<v;++j)if(a[i][j]&1) --a[i][j],++a[i][j+1],mv[++nm]=(Move){i,j,i,j+1};
			if(i<h&&(a[i][v]&1)) --a[i][v],++a[i+1][v],mv[++nm]=(Move){i,v,i+1,v};
		}
		else {
			for(register int j=v;j>1;--j)if(a[i][j]&1) --a[i][j],++a[i][j-1],mv[++nm]=(Move){i,j,i,j-1};
			if(i<h&&(a[i][1]&1)) --a[i][1],++a[i+1][1],mv[++nm]=(Move){i,1,i+1,1};
		}
	}
	printf("%d\n",nm);
	for(register int i=1;i<=nm;++i)printf("%d %d %d %d\n",mv[i].a,mv[i].b,mv[i].c,mv[i].d);
	return 0;
}