Describe the main character of the given story in two sentences.
Once upon a time, there was an old man who had three sons.
The main character of this story is an old man. He has three sons.
Complete the following task based on the instruction and optional input provided.### Instruction:
Describe the main character of the given story in two sentences.

### Input:
Once upon a time, there was an old man who had three sons.

### Output:
The main character of this story is an old man. He has three sons.