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 JAVA):

Solution:
import java.io.*;
import java.math.BigInteger;
import java.util.*;
//import java.math.*;
import java.awt.Point;
 
public class Main {
	//static final long MOD = 998244353L;
	//static final long INF = -1000000000000000007L;
	static final long MOD = 1000000007L;
	//static final int INF = 1000000007;

	public static void main(String[] args) {
		FastScanner sc = new FastScanner();
		PrintWriter pw = new PrintWriter(System.out);
		int H = sc.ni();
		int W = sc.ni();
		int[][] grid = new int[H][W];
		for (int i = 0; i < H; i++) {
			for (int j = 0; j < W; j++)
				grid[i][j] = sc.ni()%2;
		}
		ArrayList<int[]> operations = new ArrayList<int[]>();
		int row = 0;
		int col = 0;
		while (true) {
			int nextR = -1;
			int nextC = -1;
			if (row % 2 == 0) {
				if (col == W-1) {
					nextR = row+1;
					nextC = col;
				} else {
					nextR = row;
					nextC = col+1;
				}
			} else {
				if (col == 0) {
					nextR = row+1;
					nextC = col;
				} else {
					nextR = row;
					nextC = col-1;
				}
			}
			
			if (nextR == H)
				break;
			if (grid[row][col] == 1) {
				grid[row][col] = 0;
				grid[nextR][nextC] += 1;
				grid[nextR][nextC] %= 2;
				int[] op = new int[]{row+1,col+1,nextR+1,nextC+1};
				operations.add(op);
			}
			row = nextR;
			col = nextC;
		}
		pw.println(operations.size());
		for (int[] op: operations) {
			pw.println(op[0] + " " + op[1] + " " + op[2] + " " + op[3]);
		}
		pw.close();
	}
	
	static class SegmentTree {

		public long[][] ranges;

		public SegmentTree(int N) {
			ranges = new long[4*N+1][4];
		}

		//range update nums[updateL..updateR] += val;
		public void add(int n, int L, int R, int updateL, int updateR, long val) {
			push(n,L,R);
			if (updateL <= L && R <= updateR) {
				//fully contained
				ranges[n][3] += val;
				push(n,L,R);
				return;
			} else if (L>updateR || R<updateL || L==R) {
				//not contained at all or leaf
				return;
			}
			add(2*n,L,(L+R)/2,updateL,updateR,val); 
			add(2*n+1,(L+R)/2+1,R,updateL,updateR,val);
			ranges[n][1] = Math.min(ranges[2*n][1],ranges[2*n+1][1]);
			ranges[n][2] = Math.max(ranges[2*n][2],ranges[2*n+1][2]);
			ranges[n][0] = ranges[2*n][0] + ranges[2*n+1][0];
		}

		public long minQuery(int n, int L, int R, int Lq, int Rq) {
			push(n,L,R);
			if (Lq <= L && R <= Rq) {
				return ranges[n][1];
			} else if (R < Lq || Rq < L || L==R) {
				return 1000000000000007L;
			} else {
				return Math.min(minQuery(2*n,L,(L+R)/2,Lq,Rq),minQuery(2*n+1,(L+R)/2+1,R,Lq,Rq));
			}
		}

		public long maxQuery(int n, int L, int R, int Lq, int Rq) {
			push(n,L,R);
			if (Lq <= L && R <= Rq) {
				return ranges[n][2];
			} else if (R < Lq || Rq < L || L==R) {
				return -1L;
			} else {
				return Math.max(maxQuery(2*n,L,(L+R)/2,Lq,Rq),maxQuery(2*n+1,(L+R)/2+1,R,Lq,Rq));
			}
		}

		public long sumQuery(int n, int L, int R, int Lq, int Rq) {
			push(n,L,R);
			if (Lq <= L && R <= Rq) {
				return ranges[n][0];
			} else if (R < Lq || Rq < L || L==R) {
				return 0L;
			} else {
				return (sumQuery(2*n,L,(L+R)/2,Lq,Rq) + sumQuery(2*n+1,(L+R)/2+1,R,Lq,Rq));
			}
		}

		public void push(int n, int L, int R) {
			ranges[n][1] += ranges[n][3];
			ranges[n][2] += ranges[n][3];
			ranges[n][0] += (R-L+1)*ranges[n][3];

			if (L < R) {
				ranges[2*n][3] += ranges[n][3];
				ranges[2*n+1][3] += ranges[n][3];
			}

			ranges[n][3] = 0;
		}
	}

	public static long dist(long[] p1, long[] p2) {
		return (Math.abs(p2[0]-p1[0])+Math.abs(p2[1]-p1[1]));
	}
	
	//Find the GCD of two numbers
	public static long gcd(long a, long b) {
		if (a < b) return gcd(b,a);
		if (b == 0)
			return a;
		else
			return gcd(b,a%b);
	}
	
	//Fast exponentiation (x^y mod m)
	public static long power(long x, long y, long m) { 
		long ans = 1;
		x %= m;
		while (y > 0) { 
			if(y % 2 == 1) 
				ans = (ans * x) % m; 
			y /= 2;  
			x = (x * x) % m;
		} 
		return ans; 
	}
	
	public static int[][] shuffle(int[][] array) {
		Random rgen = new Random();
		for (int i = 0; i < array.length; i++) {
		    int randomPosition = rgen.nextInt(array.length);
		    int[] temp = array[i];
		    array[i] = array[randomPosition];
		    array[randomPosition] = temp;
		}
		return array;
	}
	
    public static int[][] sort(int[][] array) {
    	//Sort an array (immune to quicksort TLE)
 
		Arrays.sort(array, new Comparator<int[]>() {
			  @Override
        	  public int compare(int[] arr1, int[] arr2) {
				  return arr1[0]-arr2[0]; //ascending order
	          }
		});
		return array;
	}
    
    public static long[][] sort(long[][] array) {
    	//Sort an array (immune to quicksort TLE)
		Random rgen = new Random();
		for (int i = 0; i < array.length; i++) {
		    int randomPosition = rgen.nextInt(array.length);
		    long[] temp = array[i];
		    array[i] = array[randomPosition];
		    array[randomPosition] = temp;
		}
		Arrays.sort(array, new Comparator<long[]>() {
			  @Override
        	  public int compare(long[] arr1, long[] arr2) {
				  //return 0;
				  if (arr1[0] < arr2[0]) {
					  return -1;
				  } else if (arr1[0] > arr2[0]) {
					  return 1;
				  } else {
					  return 0;
				  }
	          }
		});
		return array;
	}
    
    static class FastScanner { 
        BufferedReader br; 
        StringTokenizer st; 
  
        public FastScanner() { 
            br = new BufferedReader(new InputStreamReader(System.in)); 
        } 
  
        String next() { 
            while (st == null || !st.hasMoreElements()) { 
                try { 
                    st = new StringTokenizer(br.readLine());
                } catch (IOException  e) { 
                    e.printStackTrace(); 
                } 
            } 
            return st.nextToken(); 
        } 
  
        int ni() { 
            return Integer.parseInt(next()); 
        } 
  
        long nl() { 
            return Long.parseLong(next()); 
        } 
  
        double nd() { 
            return Double.parseDouble(next()); 
        } 
  
        String nextLine() { 
            String str = ""; 
            try { 
                str = br.readLine(); 
            } catch (IOException e) {
                e.printStackTrace(); 
            } 
            return str;
        }
    }
}