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.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public class Main {
 
  private static void solve() {
    int h = ni();
    int w = ni();
    int[][] a = ntable(h, w);
    List<String> list = new ArrayList<>();
    for (int i = 0; i < h; i++) {
      if (i % 2 == 0) {
        for (int j = 0; j < w; j++) {
          if (a[i][j] % 2 == 1) {
            if (j < w - 1) {
              list.add((i + 1) + " " + (j + 1) + " " + (i + 1) + " " + (j + 2));
              a[i][j] --;
              a[i][j + 1] ++;
            } else if (i < h - 1) {
              list.add((i + 1) + " " + (j + 1) + " " + (i + 2) + " " + (j + 1));
              a[i][j] --;
              a[i + 1][j] ++;
            }
          }
        }
      } else {
        for (int j = w - 1; j >= 0 ; j--) {
          if (a[i][j] % 2 == 1) {
            if (j > 0) {
              list.add((i + 1) + " " + (j + 1) + " " + (i + 1) + " " + j);
              a[i][j] --;
              a[i][j - 1] ++;
            } else if (i < h - 1) {
              list.add((i + 1) + " " + (j + 1) + " " + (i + 2) + " " + (j + 1));
              a[i][j] --;
              a[i + 1][j] ++;
            }
          }
        }
      }
    }
    //out.println(Arrays.deepToString(a));
    out.println(list.size());
    for (String s : list) {
      out.println(s);
    }
  }
 
  public static void main(String[] args) {
    new Thread(null, new Runnable() {
      @Override
      public void run() {
        long start = System.currentTimeMillis();
        String debug = args.length > 0 ? args[0] : null;
        if (debug != null) {
          try {
            is = java.nio.file.Files.newInputStream(java.nio.file.Paths.get(debug));
          } catch (Exception e) {
            throw new RuntimeException(e);
          }
        }
        reader = new java.io.BufferedReader(new java.io.InputStreamReader(is), 32768);
        solve();
        out.flush();
        tr((System.currentTimeMillis() - start) + "ms");
      }
    }, "", 64000000).start();
  }
 
  private static java.io.InputStream is = System.in;
  private static java.io.PrintWriter out = new java.io.PrintWriter(System.out);
  private static java.util.StringTokenizer tokenizer = null;
  private static java.io.BufferedReader reader;
 
  public static String next() {
    while (tokenizer == null || !tokenizer.hasMoreTokens()) {
      try {
        tokenizer = new java.util.StringTokenizer(reader.readLine());
      } catch (Exception e) {
        throw new RuntimeException(e);
      }
    }
    return tokenizer.nextToken();
  }
 
  private static double nd() {
    return Double.parseDouble(next());
  }
 
  private static long nl() {
    return Long.parseLong(next());
  }
 
  private static int[] na(int n) {
    int[] a = new int[n];
    for (int i = 0; i < n; i++)
      a[i] = ni();
    return a;
  }
 
  private static char[] ns() {
    return next().toCharArray();
  }
 
  private static long[] nal(int n) {
    long[] a = new long[n];
    for (int i = 0; i < n; i++)
      a[i] = nl();
    return a;
  }
 
  private static int[][] ntable(int n, int m) {
    int[][] table = new int[n][m];
    for (int i = 0; i < n; i++) {
      for (int j = 0; j < m; j++) {
        table[i][j] = ni();
      }
    }
    return table;
  }
 
  private static int[][] nlist(int n, int m) {
    int[][] table = new int[m][n];
    for (int i = 0; i < n; i++) {
      for (int j = 0; j < m; j++) {
        table[j][i] = ni();
      }
    }
    return table;
  }
 
  private static int ni() {
    return Integer.parseInt(next());
  }
 
  private static void tr(Object... o) {
    if (is != System.in)
      System.out.println(java.util.Arrays.deepToString(o));
  }
 }