2831: Special Matrices
Description
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.
The first line of the input contains three integers n, m, mod (2≤n≤500, 0≤m≤n, 2≤mod≤109). Then m lines follow, each of them contains n characters − the first rows of the required special matrices. Each of these lines contains exactly two characters '1', the rest characters are '0'. Each column of the given m×n table contains at most two numbers one.
Print the remainder after dividing the required value by number mod.
3 1 1000
011
2
4 4 100500
0110
1010
0101
1001
1
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.