Letter Matching (APCS 2025-11 Expert)

2.0s 256M

There are \(k\) stacks of cards, each card bearing an uppercase letter and a score. In one operation, remove the top cards of two different stacks if their letters match, earning their combined score. Zero or more operations are allowed. Maximize the total score.

Input Format

Read \(k\). Each following row describes a stack: its size \(n_i\), then its letter-score pairs from top to bottom.

Output Format

Print the maximum total score.

Constraints

\(2\le k\le6\); \(0\le n_i\le12\). Letters are A through Z; scores are \(1\) through \(10\).

Scoring

  • 30 points: \(k=3\).
  • 70 points: no additional restrictions.

Each scored test is worth 5 points.

Sample Input 1

3
3 A 1 B 2 C 1
3 B 2 A 2 A 1
3 A 1 B 1 C 1

Sample Output 1

7

Sample Input 2

3
3 X 1 A 1 A 1
2 Y 1 A 1
3 Z 1 A 1 A 1

Sample Output 2

0

Source

APCS 2025-11 High Level, based on the public reconstruction: ZeroJudge r626。

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