Categorize the following list of items according to material: wood, steel, plastic, aluminum
Chair, Hammer, Pen, Bottle
- Wood: Chair 
- Steel: Hammer 
- Plastic: Pen, Bottle 
- Aluminum: None
Complete the following task based on the instruction and optional input provided.### Instruction:
Categorize the following list of items according to material: wood, steel, plastic, aluminum

### Input:
Chair, Hammer, Pen, Bottle

### Output:
- Wood: Chair 
- Steel: Hammer 
- Plastic: Pen, Bottle 
- Aluminum: None