Problem:
Score : 400 points

Problem Statement

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.

Sample Input 1

2 3
1 2 3
0 1 1

Sample Output 1

3
2 2 2 3
1 1 1 2
1 3 1 2

Every cell contains an even number of coins after the following sequence of operations:

Move the coin in Cell (2, 2) to Cell (2, 3).

Move the coin in Cell (1, 1) to Cell (1, 2).

Move one of the coins in Cell (1, 3) to Cell (1, 2).

Sample Input 2

3 2
1 0
2 1
1 0

Sample Output 2

3
1 1 1 2
1 2 2 2
3 1 3 2

Sample Input 3

1 5
9 9 9 9 9

Sample Output 3

2
1 1 1 2
1 3 1 4

Solution in C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Diagnostics;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using System.Numerics;
using System.IO;
using System.Runtime.InteropServices;
using static System.Math;
using static Math2;
using static io;
using static Utils;

public class ACCEPTED
{
    public void Solve()
    {
        var o = Intm;
        var H = o[0];
        var W = o[1];
        var a = new int[H][];
        for (int i = 0; i < H; ++i) a[i] = Intm;
        var c = new List<Tuple<int, int, int, int>>();
        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 (i == H - 1 && j == W - 1) continue;
                        else if (j == W - 1)
                        {
                            a[i + 1][W - 1]++;
                            c.Add(new Tuple<int, int, int, int>(i + 1, j + 1, i + 2, W));
                        }
                        else
                        {
                            a[i][j + 1]++;
                            c.Add(new Tuple<int, int, int, int>(i + 1, j + 1, i + 1, j + 2));
                        }
                    }

                }
            }
            else
            {
                for (int j = W - 1; j >= 0; --j)
                {
                    if (a[i][j] % 2 == 1)
                    {
                        if (i == H - 1 && j == 0) continue;
                        else if (j == 0)
                        {
                            a[i + 1][0]++;
                            c.Add(new Tuple<int, int, int, int>(i + 1, j + 1, i + 2, 1));
                        }
                        else
                        {
                            a[i][j - 1]++;
                            c.Add(new Tuple<int, int, int, int>(i + 1, j + 1, i + 1, j));
                        }

                    }
                }
            }
        }
        Write(c.Count);
        foreach (var x in c)
        {
            Write(x.Item1, x.Item2, x.Item3, x.Item4);
        }
    }
}

public static class Graph
{

}


public static class Math2
{
    public const int INF = 1 << 29;
    public const long INFL = 1L << 60;
    public const int MOD = 1000000007;
    public const int MOD2 = 998244353;

    public static long Pow(long i, long N, long MOD = 1000000007)
    {
        long res = 1;
        while (N > 0)
        {
            if ((N & 1) != 0) res = res * i % MOD;
            i = i * i % MOD;
            N >>= 1;
        }
        return res;
    }
    public static long GCD(long i, long N)
    {
        if (i > N) Swap(ref i, ref N);
        if (i == 0) return N;
        while (N != 0)
        {
            var r = i % N;
            i = N;
            N = r;
        }
        return i;
    }
    public static long LCM(long i, long N) => i * N / GCD(i, N);
    public static long Comb(long N, long R, int MOD = 1000000007)
    {
        long ret = 1;
        long x = 1;
        for (long i = N; i >= N - R + 1; --i)
        {
            ret = ret / x * i;
            ret %= MOD;
            x++;
        }
        return ret;
    }
    public static long Comb2(long N, long R)
    {
        long Nume = 1;
        long Deno = 1;

        if (R > N - R) Swap(ref N, ref R);
        for (long i = 1; i <= R; ++i)
        {
            Deno *= i;
            Nume *= N - i + 1;
        }
        return Deno / Nume;
    }
    public static Dictionary<long, int> PrimeFactorization(long N)
    {
        var ret = new Dictionary<long, int>();
        for (long i = 2; i * i <= N; ++i)
        {
            int cnt = 0;
            while (N % i == 0)
            {
                cnt++;
                N /= i;
            }
            if (cnt != 0) ret[i] = cnt;
        }
        if (N >= 2) ret[N] = 1;
        return ret;
    }
    public static List<long> DivisorEnumrate(long N)
    {
        var ret = new List<long>();
        for (long i = 1; i * i <= N; ++i)
        {
            if (N % i == 0)
            {
                ret.Add(i);
                ret.Add(N / i);
            }
        }
        return ret;
    }
}
public static class Utils
{
    public static void Swap<T>(ref T A, ref T B)
    {
        T x = A;
        A = B;
        B = x;
    }
    public static int DigitSum(int N)
    {
        string s = N.ToString();
        int ret = 0;
        for (int i = 0; i < s.Length; ++i) ret += s[i] - '0';
        return ret;
    }
}
class Program
{
    static void Main(string[] args)
    {
        var ACCEPTED = new ACCEPTED();
        ACCEPTED.Solve();
    }
}
public static class io
{
    public static string Str => Console.ReadLine();
    public static string[] Strm => Str.Split(' ');
    public static long[] Longm => Strm.Select(long.Parse).ToArray();
    public static int[] Intm => Strm.Select(int.Parse).ToArray();
    public static char[] Charm => Str.ToArray();
    public static double[] Doublem => Strm.Select(double.Parse).ToArray();
    public static long Long1 => Longm[0];
    public static int Int1 => Intm[0];
    public static char Char1 => Charm[0];
    public static double Double1 => Doublem[0];
    public static long[] HorizontalRead(int N) { long[] A = new long[N]; for (int i = 0; i < N; ++i) A[i] = Long1; return A; }
    public static void Write(string a) => Console.WriteLine(a);
    public static void Write(params object[] i) => Write(string.Join(" ", i));
    public static void Write<T>(IEnumerable<T> a) => Write(string.Join(" ", a));
    public static void Horizontalwrite<T>(IEnumerable<T> a) { foreach (var z in a) Write(z); }
    public static void YN(bool i) { if (i) Write("Yes"); else Write("No"); }
}