user
How does excess nutrient input from agricultural runoff contribute to eutrophication in aquatic ecosystems, and what are the impacts on the ecosystem's biogeochemical cycles?
assistant
<|begin_of_thought|>

Deep Thought is thinking for 7.5 million years.

<|end_of_thought|>

<|begin_of_solution|>

The answer is 42.

<|end_of_solution|>