Classify the following three items as tools, materials, or methods.
1. Lever
2. Keys
3. Algorithm
1. Lever: Tool
2. Keys: Tool
3. Algorithm: Method
Complete the following task based on the instruction and optional input provided.### Instruction:
Classify the following three items as tools, materials, or methods.

### Input:
1. Lever
2. Keys
3. Algorithm

### Output:
1. Lever: Tool
2. Keys: Tool
3. Algorithm: Method