题目描述
Problem Statement
We have N switches with "on" and "off" state, and M bulbs. The switches are numbered 1 to N, and the bulbs are numbered 1 to M.
Bulb i is connected to k_i switches: Switch s_{i1}, s_{i2}, ..., and s_{ik_i}. It is lighted when the number of switches that are "on" among these switches is congruent to p_i modulo 2.
How many combinations of "on" and "off" states of the switches light all the bulbs?
Input
Input is given from Standard Input in the following format:
N M
k_1 s_{11} s_{12} ... s_{1k_1}
:
k_M s_{M1} s_{M2} ... s_{Mk_M}
p_1 p_2 ... p_M
Output
Print the number of combinations of "on" and "off" states of the switches that light all the bulbs.
Constraints
- $1 \leq N, M \leq 10$
- $1 \leq k_i \leq N$
- $1 \leq s_{ij} \leq N$
- $s_{ia} \neq s_{ib} (a \neq b)$
- p_i is 0 or 1.
- All values in input are integers.
Sample Input 1
2 2
2 1 2
1 2
0 1
Sample Output 1
1
- Bulb 1 is lighted when there is an even number of switches that are "on" among the following: Switch 1 and 2.
- Bulb 2 is lighted when there is an odd number of switches that are "on" among the following: Switch 2.
There are four possible combinations of states of (Switch 1, Switch 2): (on, on), (on, off), (off, on) and (off, off). Among them, only (on, on) lights all the bulbs, so we should print 1.
Sample Input 2
2 3
2 1 2
1 1
1 2
0 0 1
Sample Output 2
0
- Bulb 1 is lighted when there is an even number of switches that are "on" among the following: Switch 1 and 2.
- Bulb 2 is lighted when there is an even number of switches that are "on" among the following: Switch 1.
- Bulb 3 is lighted when there is an odd number of switches that are "on" among the following: Switch 2.
Switch 1 has to be "off" to light Bulb 2 and Switch 2 has to be "on" to light Bulb 3, but then Bulb 1 will not be lighted. Thus, there are no combinations of states of the switches that light all the bulbs, so we should print 0.
Sample Input 3
5 2
3 1 2 5
2 2 3
1 0
Sample Output 3
8
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分