
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
If the cosines of the three interior angles of $\triangle A_{1}B_{1}C_{1}$ are respectively equal to the sines of the three interior angles of $\triangle A_{2}B_{2}C_{2}$, then the correct conclusion is __________.  
① Both $\triangle A_{1}B_{1}C_{1}$ and $\triangle A_{2}B_{2}C_{2}$ are acute triangles  
② Both $\triangle A_{1}B_{1}C_{1}$ and $\triangle A_{2}B_{2}C_{2}$ are obtuse triangles  
③ $\triangle A_{1}B_{1}C_{1}$ is an obtuse triangle, and $\triangle A_{2}B_{2}C_{2}$ is an acute triangle  
④ $\triangle A_{1}B_{1}C_{1}$ is an acute triangle, and $\triangle A_{2}B_{2}C_{2}$ is an obtuse triangle．

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