CF704C Black Widow
Description
Natalia Romanova is trying to test something on the new gun S.H.I.E.L.D gave her. In order to determine the result of the test, she needs to find the number of answers to a certain equation. The equation is of form:
Where  represents logical OR and  represents logical exclusive OR (XOR), and $ v_{i,j} $ are some boolean variables or their negations. Natalia calls the left side of the equation a XNF formula. Each statement in brackets is called a clause, and $ v_{i,j} $ are called literals.
In the equation Natalia has, the left side is actually a 2-XNF-2 containing variables $ x_{1},x_{2},...,x_{m} $ and their negations. An XNF formula is 2-XNF-2 if:
1. For each $ 1
Input Format
N/A
Output Format
N/A
Explanation/Hint
The equation in the first sample is:
The equation in the second sample is:
The equation in the third sample is:
