
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
There are 13 doctors, among which there are 6 female doctors. Now, 5 doctors are selected to form a medical team to go to the disaster area. If the medical team must have at least 2 male doctors and at most 3 female doctors, let the number of different methods of selection be $N$. Then, among the following equations: ① $C_{13}^{5} - C_{7}^{1}C_{6}^{4}$; ② $C_{7}^{2}C_{6}^{3} + C_{7}^{3}C_{6}^{2} + C_{7}^{4}C_{6}^{1} + C_{7}^{5}$; ③ $C_{13}^{5} - C_{7}^{1}C_{6}^{4} - C_{6}^{5}$; ④ $C_{7}^{2}C_{11}^{3}$;  
the equations that can represent $N$ are.

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