题目描述
Problem Statement
We have N locked treasure boxes, numbered 1 to N.
A shop sells M keys. The i-th key is sold for a_i yen (the currency of Japan), and it can unlock b_i of the boxes: Box c_{i1}, c_{i2}, ..., c_{i{b_i}}. Each key purchased can be used any number of times.
Find the minimum cost required to unlock all the treasure boxes. If it is impossible to unlock all of them, print -1.
Input
Input is given from Standard Input in the following format:
N M
a_1 b_1
c_{11} c_{12} ... c_{1{b_1}}
:
a_M b_M
c_{M1} c_{M2} ... c_{M{b_M}}
Output
Print the minimum cost required to unlock all the treasure boxes.
If it is impossible to unlock all of them, print -1.
Constraints
- All values in input are integers.
- $1 \leq N \leq 12$
- $1 \leq M \leq 10^3$
- $1 \leq a_i \leq 10^5$
- $1 \leq b_i \leq N$
- $1 \leq c_{i1} < c_{i2} < ... < c_{i{b_i}} \leq N$
Sample Input 1
2 3
10 1
1
15 1
2
30 2
1 2
Sample Output 1
25
We can unlock all the boxes by purchasing the first and second keys, at the cost of 25 yen, which is the minimum cost required.
Sample Input 2
12 1
100000 1
2
Sample Output 2
-1
We cannot unlock all the boxes.
Sample Input 3
4 6
67786 3
1 3 4
3497 1
2
44908 3
2 3 4
2156 3
2 3 4
26230 1
2
86918 1
3
Sample Output 3
69942
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分