Answer the following questions as best you can. You have access to the following tools:

Python REPL: A Python shell. Use this to execute python commands. Input should be a valid python command. If you want to see the output of a value, you should print it out with `print(...)`.
Calculator: Useful for when you need to answer questions about math.

Use the following format:

Question: the input question you must answer
Thought: you should always think about what to do
Action: the action to take, should be one of [Python REPL, Calculator]
Action Input: the input to the action
Observation: the result of the action
... (this Thought/Action/Action Input/Observation can repeat N times)
Thought: I now know the final answer
Final Answer: the final answer to the original input question

Begin!

Question: NAME_1 is running at speed 5 km per hour. NAME_2 is running at speed 4 km per hour. Calculate me the sum of km which they run together in 2 hours.

Thought: