
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 ellipse $\frac{x^{2}}{a^{2}}+\frac{y^{2}}{b^{2}}=1 (a>b>0)$ and the line $x+y=1$ intersect at points $M$ and $N$, and $OM \perp ON$ (where $O$ is the origin), when the eccentricity $e \in\left[-\frac{3}{3}, \overline{2}\right]$, find the range of values for the length of the major axis of the ellipse.

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