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;
int main(){
  int h, w; cin >> h >> w;
  vector<int> d(h*w);
  for (int i = 0; i < h; i++) {
    for (int j = 0; j < w; j++) {
      int t;
      if (i % 2 == 0) t = i * w + j;
      else t = (i+1) * w - j-1;
      cin >> d[t];
    }
  }
  vector<pair<int, int>> x, y;
  for (int i = 0; i < h*w-1; i++) {
    if (d[i] % 2) {
      d[i]--; d[i+1]++;
      int a = i % w; int b = i / w;
      if (b % 2) a = w-a-1;
      x.push_back({b+1, a+1});
      a = (i+1) % w; b = (i+1) / w;
      if (b % 2) a = w-a-1;
      y.push_back({b+1, a+1});
    }
  }
  cout << x.size() << endl;
  for (int i = 0; i < (int) x.size(); i++) {
    cout << x[i].first << " " << x[i].second << " " << y[i].first << " " << y[i].second << endl;
  }
  return 0;
}