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

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: if needed, the action to take, should be one of [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: Who is the current president of the US?
Thought: