
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
The names of three friends are Kostya, Vasya, and Kolya. Their last names are Semyonov, Burov, and Nikolaev. Whose last name is which is unknown. However, it is known that Semyonov's grandfather is the biological brother of their neighbor Petrov, Kostya is one year older than Kolya, and Kolya is one year older than Nikolaev. The sum of their ages is more than 49 but less than 53. Kolya's mother is the daughter of the well-known Professor Korobov. Determine the last names of the friends and each of their ages.

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