
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
Anderson and Brown need to cover a distance of 20 km and arrive at the destination simultaneously. They have only one bicycle between them. Anderson can walk at a speed of 4 km/h and Brown can walk at a speed of 5 km/h. On the bicycle, Anderson can ride at a speed of 10 km/h while Brown can ride at a speed of 8 km/h. Where should they change the bicycle? Each of them either rides the bicycle or walks on foot without taking any breaks along the way.

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