SOLVE
LATER
Given a bipartite graph having N vertices in each part and M edges, find the number of perfect matchings in it modulo 4.
Input format:
First line consists of a single integer T denoting the number of test cases.
First line of each case consists of two space separated integers denoting N and M.
Each of the following M lines consists of two space separated integers u and v, denoting that there is an edge between
vertex numbered u on the left side and vertex numbered v on the right side. Vertices on each side are enumerated independently starting from 0.
Output format:
For each test case, print a single number in a new line - number of perfect matchings modulo 4
Constraints:
\(1 \le T \le 10\)
\(1 \le N \le 50\)
\(0 \le M \le N * N\)
\(0 \le u, v \le N-1\)