D - Make Them Even

Time Limit: 2 sec / Memory Limit: 1024 MB

問題文

H 行横 W 列に区切られたマス目があり、上から i 番目、左から j 列目のマスをマス (i, j) と呼びます。

マス (i, j) には a_{ij} 枚のコインが置かれています。

あなたは以下の操作を何度でも行うことができます。

制約

• 入力はすべて整数である
• 1 \leq H, W \leq 500
• 0 \leq a_{ij} \leq 9

入力

H W
a_{11} a_{12} ... a_{1W}
a_{21} a_{22} ... a_{2W}
:
a_{H1} a_{H2} ... a_{HW}


出力

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'


すなわち、1 行目には操作の回数を表す 0 以上 H \times W 以下の整数 N を出力せよ。

i+1 (1 \leq i \leq N) 行目には i 回目の操作を表す整数 y_i, x_i, y_i', x_i' (1 \leq y_i, y_i' \leq H かつ 1 \leq x_i, x_i' \leq W) を出力せよ。 ただし、これはマス (y_i, x_i) にあるコインのうち 1 枚を上下左右に隣接するマス (y_i', x_i') に移動させる操作を表す。

入力例 1

2 3
1 2 3
0 1 1


出力例 1

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


• マス (2, 2) に置かれているコインのうち 1 枚をマス (2, 3) に移動します
• マス (1, 1) に置かれているコインのうち 1 枚をマス (1, 2) に移動します
• マス (1, 3) に置かれているコインのうち 1 枚をマス (1, 2) に移動します

入力例 2

3 2
1 0
2 1
1 0


出力例 2

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


入力例 3

1 5
9 9 9 9 9


出力例 3

2
1 1 1 2
1 3 1 4


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