Extracting Values from String for Proper Structured Outputs

I’m trying to extract values from a string that looks like this: "doors":80,"total_door_count":200 I want to calculate vacant_units as 5% of total_door_count and return all 3 values cleanly. I tried using a Use AI block with Fields, but I keep getting 0 or missing fields. What’s the best way to extract those and return proper structured outputs?