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