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<iostream>
#include<cstdio>
#include<vector>

using namespace std;

struct data{
	int a,b,c,d;
	data():a(0),b(0),c(0),d(0){}
	data(int m,int n,int p,int q):a(m),b(n),c(p),d(q){}
};

vector<data> vec;
int h,w,a[501][501],b[501][501];

int main(){
	scanf("%d%d",&h,&w);
	for(int i=1;i<=h;++i)for(int j=1;j<=w;++j)scanf("%d",&a[i][j]),b[i][j]=a[i][j]%2;
	for(int i=1;i<=h;++i)for(int j=1;j<=w;++j){
		if(i>1&&b[i-1][j]==1)b[i-1][j]^=1,b[i][j]^=1,vec.push_back(data(i-1,j,i,j));
		if(j>1&&b[i][j-1]==1)b[i][j-1]^=1,b[i][j]^=1,vec.push_back(data(i,j-1,i,j));
	}
	printf("%d\n",vec.size());
	for(data dt:vec)printf("%d %d %d %d\n",dt.a,dt.b,dt.c,dt.d);
}