Table: mutsuki - class destroyer
Question: Which builder built the most class destroyers with less than a year between the laid-down and completion dates?
Step 1 (Operation, Indexing): builder
Step 2 (Operation, Grouping): builder
Step 3 (Reasoning, Aggregating): COUNT, builder
Step 4 (Reasoning, Other Commonsense Reasoning): less than a year
Answer: fujinagata shipyards , japan