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>
#define r(i,n) for(int i=0;i<n;i++)
using namespace std;
int h,w,a[555][555],z[500*500+7],x[500*500+7],c[500*500+7],v[500*500+7];
signed main(){
  cin>>h>>w;
  r(i,h)r(j,w)cin>>a[i][j],a[i][j]%=2;
  int cnt=0;
  r(i,h)r(j,w-1){
    if(a[i][j]){
      z[cnt]=i;
      x[cnt]=j;
      c[cnt]=i;
      v[cnt]=j+1;
      a[i][j]=0;
      a[i][j+1]=(a[i][j+1]+1)%2;
      cnt++;
    }
  }
  r(i,h-1){
    int j=w-1;
    if(a[i][j]){
      z[cnt]=i;
      x[cnt]=j;
      c[cnt]=i+1;
      v[cnt]=j;
      a[i][j]=0;
      a[i+1][j]=(a[i+1][j]+1)%2;
      cnt++;
    }
  }
  cout<<cnt<<endl;
  r(i,cnt){
    cout<<z[i]+1<<' '<<x[i]+1<<' '<<c[i]+1<<' '<<v[i]+1<<endl;
  }
}