
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
Given the following four pairs of events:

1. A person shoots once, "hitting the 7 ring" and "hitting the 8 ring";
2. Two people, A and B, each shoot once, "at least one person hits the target" and "A hits, but B does not hit the target";
3. Two balls are randomly drawn from a pocket containing 2 red balls and 2 black balls, "at least one black ball" and "both are red balls";
4. Two balls are randomly drawn from a pocket containing 2 red balls and 2 black balls, "no black balls" and "exactly one red ball".

Identify the pair(s) of mutually exclusive events by filling in the blank with the corresponding number(s).

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