Score : 400 points
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.
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}
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.
2 3 1 2 3 0 1 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:
3 2 1 0 2 1 1 0
3 1 1 1 2 1 2 2 2 3 1 3 2
1 5 9 9 9 9 9
2 1 1 1 2 1 3 1 4