
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 that vector $$\overrightarrow {a}$$ = (1, -1), vector $$\overrightarrow {a}$$ - 2 * vector $$\overrightarrow {b}$$ = (k - 1, 2k + 2), and vector $$\overrightarrow {a}$$ is orthogonal to vector $$\overrightarrow {b}$$, find the value of k.

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