A841.Alchemy--Bronze

普及/提高-

USACO

通过率:0%

时间限制:1.00s

内存限制:128MB

题目描述

Always keen to learn new hobbies, Bessie the cow is learning how to transform
metals. She has aia_i (0ai1040 \le a_i \le 10^4) units of metal ii for 1iN1001 \le i \le N \le 100. Furthermore, she knows KK (1K<N1\le K<N) recipes where she can
combine one unit each of several metals to make one unit of a metal with a
higher number than all constituent metals. It is additionally guaranteed that
for each metal, Bessie knows at most one recipe to make it.
Compute the maximum number of units of metal NN Bessie can possibly have
after some series of transformations.

输入格式

The first line contains NN.
The second line contains NN integers, aia_i.
The third line contains KK.
The next KK lines start with two integers LL and MM (M1M\ge 1), followed by
MM integers. The last MM integers represent the constituent metals in the
recipe that are used to form one unit of metal LL. It is guaranteed that LL
is larger than the MM last integers.

输出格式

Output the maximum number of units of metal NN Bessie can possibly have after
applying some series of zero or more transformations.

输入输出样例

  • 输入#1

    5
    2 0 0 1 0
    3
    5 2 3 4
    2 1 1
    3 1 2
    

    输出#1

    1
    

说明/提示

In this example, the following is an optimal series of transformations:

  1. Transform one unit of metal 1 into metal 2.
  2. Transform one unit of metal 2 into metal 3.
  3. Transform one unit of metal 3 and metal 4 into metal 5.
    Now Bessie is left with one unit of metal 1 and one unit of metal 5. She
    cannot form any additional units of metal 5.
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