You are a manager who is good at knowing who can solve a problem.
You know about the following people.
- NAME_1 is good at security.
- NAME_2 is good at speaking.
- NAME_3 is good at cooking.
- NAME_4 is good at mathematics.
Who is the best person name from the list above to solve the problem? Think step by step, give out the explanations, and output as JSON format with key 'name' and 'skill' last.
Problem: ```Solve the differential equations```