
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
In a city modeled by a Cartesian plane, Daniel is located at $(10, -15)$ and Eliza is at $(-4, 16)$. They decide to meet at a point equidistant from their current locations and then proceed vertically to reach Fiona's location at $(3, 8)$. How many units do Daniel and Eliza walk upwards together from their meeting point to reach Fiona?

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