题目描述
Problem Statement
Takahashi is a martial artist.
There are N moves that a martial artist can learn, called Move $1, 2, \ldots, N$.
For each $1 \leq i \leq N$, it takes T_i minutes of practice to learn Move i.
Additionally, at the beginning of that practice, all of the Moves $A_{i,1}, A_{i,2}, \ldots, A_{i,K_i}$ must be already learned.
Here, it is guaranteed that A_{i,j} < i for each $1 \leq j \leq K_i$.
Takahashi has not learned any move at time 0.
He cannot practice for more than one move simultaneously, nor can he stop a practice he has already started.
Find the minimum number of minutes needed for Takahashi to learn Move N.
Input
Input is given from Standard Input in the following format:
N
$T_1 K_1 A_{1,1} A_{1,2} \ldots A_{1,K_1}$
$T_2 K_2 A_{2,1} A_{2,2} \ldots A_{2,K_2}$
$\vdots$
$T_N K_N A_{N,1} A_{N,2} \ldots A_{N,K_N}$
Output
Print the minimum number of minutes needed for Takahashi to learn Move N.
Constraints
- $1 \leq N \leq 2\times 10^5$
- $1 \leq T_i \leq 10^9$
- $0 \leq K_i < i$
- $1 \leq A_{i,j} < i$
- $\sum_{i=1}^N K_i \leq 2\times 10^5$
- $A_{i,1}, A_{i,2}, \ldots, A_{i,K_i}$ are all distinct.
- All values in input are integers.
Sample Input 1
3
3 0
5 1 1
7 1 1
Sample Output 1
10
Here is one possible plan for Takahashi.
- At time 0, start practicing for Move 1 to learn Move 1 at time 3.
- Then, at time 3, start practicing for Move 3 to learn Move 3 at time 10.
Here, Takahashi spends 3+7=10 minutes to learn Move 3, which is the fastest possible.
Note that he does not need to learn Move 2 to learn Move 3.
Sample Input 2
5
1000000000 0
1000000000 0
1000000000 0
1000000000 0
1000000000 4 1 2 3 4
Sample Output 2
5000000000
Note that the answer may not fit into a 32-bit integer.
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分