Classify the following words as noun, verb, adjective or other.
- run
- gray
- book
- run - Verb
- gray - Adjective
- book - Noun
Complete the following task based on the instruction and optional input provided.### Instruction:
Classify the following words as noun, verb, adjective or other.

### Input:
- run
- gray
- book

### Output:
- run - Verb
- gray - Adjective
- book - Noun