An
n×n square matrix is
special, if:
-
it is binary, that is, each cell contains either a 0, or a 1;
-
the number of ones in each row and column equals 2.
You are given
n and the first
m rows of the matrix. Print the number of special
n×n matrices, such that the first
m rows coincide with the given ones.
As the required value can be rather large, print the remainder after dividing the value by the given number
mod.
Output
Print the remainder after dividing the required value by number
mod.
Note
For the first test the required matrices are:
011
101
110
011
110
101
In the second test the required matrix is already fully given, so the answer is 1.