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 PYTHON):

Solution:
import sys
from collections import deque
import copy


def get_read_func(fileobject):
    if fileobject == None :
        return raw_input
    else:
        return fileobject.readline

def main():
    if len(sys.argv) > 1:
        f = open(sys.argv[1])
    else:
        f = None
    read_func = get_read_func(f);
    input_raw = read_func().strip().split()
    [H, W] = [int(input_raw[0]), int(input_raw[1])]
    coin_map = [[0 for i in range(W)] for j in range(H)]
    for i in range(H):
        input_raw = read_func().strip().split()
        for j in range(W):
            coin_map[i][j] = int(input_raw[j])

    is_done = [[False for i in range(W)] for j in range(H)]
    count= 0
    next_point = (0, 0)
    ope_list = []
    move_list = [(0, 1), (0, -1), (1, 0), (-1, 0)]
    is_next_exist = True
    while is_next_exist == True:
        is_next_exist = False
        y = next_point[0]
        x = next_point[1]
        is_done[y][x] = True
        for move in move_list:
            new_y = y + move[0]
            new_x = x + move[1]
            if y>= 0 and new_y < H and new_x >= 0 and new_x < W and is_done[new_y][new_x] == False:
                next_point = (new_y, new_x)
                is_next_exist = True
                break
        if is_next_exist == False:
            break
        if coin_map[y][x] > 0 and coin_map[y][x] % 2 == 1:
            coin_map[y][x] -= 1
            coin_map[new_y][new_x] += 1
            ope_list.append((y + 1, x + 1, new_y + 1, new_x + 1))
            count += 1
    print len(ope_list)
    for ope in ope_list:
        print ope[0], ope[1], ope[2], ope[3]

if __name__ == '__main__':
    main()