Given a list of five items, categorize them.
pen, paper, food, book, computer
Writing supplies: pen, paper 
Food: food
Reading materials: book
Electronics: computer
Complete the following task based on the instruction and optional input provided.### Instruction:
Given a list of five items, categorize them.

### Input:
pen, paper, food, book, computer

### Output:
Writing supplies: pen, paper 
Food: food
Reading materials: book
Electronics: computer