Score : 500 points
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 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}}
Print the minimum cost required to unlock all the treasure boxes. If it is impossible to unlock all of them, print -1.
2 3 10 1 1 15 1 2 30 2 1 2
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.
12 1 100000 1 2
-1
We cannot unlock all the boxes.
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
69942