
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
A staircase has \( n \) steps. Each time, one can climb either one step or two steps. Let \( f(n) \) be the number of ways to reach the top of the staircase. Find the recurrence relation between \( f(n) \), \( f(n-1) \), and \( f(n-2) \).

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