
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
In the Shanghai college entrance examination reform plan, each high school student is required to choose 3 subjects from 6 subjects (3 science subjects and 3 humanities subjects) including physics, chemistry, biology, politics, history, and geography to participate in the level examination. Xiao Ding, who has better performance in science, decides to choose at least two science subjects. How many choices does Xiao Ding have?

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