
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
Seryozha and Valera started moving towards each other simultaneously: the first from point $C$, and the second from point $B$, the distance between which is 21 km. Seryozha's dog Bobik starts moving from point $C$ together with Seryozha and runs towards Valera. Meeting him, without stopping, it rushes back to meet Seryozha, after which it turns around again and runs towards Valera, and so on. They all move along the same road, with Seryozha's speed being 4 km/h, Valera's speed being 3 km/h, and Bobik's speed being 11 km/h. What is the total distance (back and forth) that Bobik runs? Justify your answer.

Present the answer in LaTex format: \boxed{Your answer}
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