
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
Let the solution set of the inequality $x(x-a-1)<0$ (where $a \in \mathbb{R}$) be $M$, and the solution set of the inequality $x^2-2x-3\leq0$ be $N$.  
(Ⅰ) When $a=1$, find the set $M$;  
(Ⅱ) If $M \subseteq N$, find the range of the real number $a$.

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