On the way to school, Karen became fixated on the puzzle game on her phone!
The game is played as follows. In each level, you have a grid withn rows andm columns. Each cell originally contains the number0.
One move consists of choosing one row or column, and adding1 to all of the cells in that row or column.
To win the level, after all the moves, the number in the cell at thei-th row andj-th column should be equal togi,?j.
Karen is stuck on one level, and wants to know a way to beat this level using the minimum number of moves. Please, help her with this task!
Input
The first line of input contains two integers,n andm (1?≤?n,?m?≤?100), the number of rows and the number of columns in the grid, respectively.
The nextn lines each containm integers. In particular, thej-th integer in thei-th of these rows containsgi,?j (0?≤?gi,?j?≤?500).
Output
If there is an error and it is actually not possible to beat the level, output a single integer-1.
Otherwise, on the first line, output a single integerk, the minimum number of moves necessary to beat the level.
The nextk lines should each contain one of the following, describing the moves in the order they must be done:
rowx, (1?≤?x?≤?n) describing a move of the form "choose thex-th row".
colx, (1?≤?x?≤?m) describing a move of the form "choose thex-th column".
If there are multiple optimal solutions, output any one of them.
Examples
input
3 5 2 2 2 3 2 0 0 0 1 0 1 1 1 2 1
output
4 row 1 row 1 col 4 row 3
input
3 3 0 0 0 0 1 0 0 0 0
output
-1
input
3 3 1 1 1 1 1 1 1 1 1
output
3 row 1 row 2 row 3
Note
In the first test case, Karen has a grid with3 rows and5 columns. She can perform the following4 moves to beat the level:
In the second test case, Karen has a grid with3 rows and3 columns. It is clear that it is impossible to beat the level; performing any move will create three1s on the grid, but it is required to only have one1 in the center.
In the third test case, Karen has a grid with3 rows and3 columns. She can perform the following3 moves to beat the level:
Note that this is not the only solution; another solution, among others, iscol 1,col 2,col 3.