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:
// D.

#include <sstream>
#include <iostream>
#include <algorithm>
#include <cstring>
#include <vector>

using namespace std;

int main(int argc, char *argv[])
{
	int h, w;
	cin >> h >> w;
	int b[500][500];
	for (int i = 0; i < h; ++i) {
		for (int j = 0; j < w; ++j) {
			cin >> b[i][j];
		}
	}
	vector<string> ans;
	int c = 0, px, py;
	for (int i = 0; i < h; ++i) {
		int st = i % 2 ? 0 : w - 1;
		int ed = i % 2 ? w : -1;
		int dir = i % 2 ? 1 : -1;
		for (int j = st; j != ed; j += dir) {
			if (c) {
				char w[64];
				sprintf(w, "%d %d %d %d", py + 1, px + 1, i + 1, j + 1);
				ans.push_back(w);
				b[i][j]++;
			}
			c = b[i][j] % 2;
			py = i, px = j;
		}
	}
	cout << ans.size() << endl;
	for (string s : ans) {
		cout << s << endl;
	}
	return 0;
}