```mermaid
flowchart LR
    B(book) -- 5 -->REC(record)
    B -- 0 --> P(poster)
    P -- 35 --> D(drums)
    REC -- 20 --> D
    REC -- 15 --> BG(bas guitar)
    P -- 30 -->BG
    BG -- 20 --> PIA(piano)
    D -- 10 --> PIA
```