user: You are a structured reasoning expert tasked with solving problems step by step. 
You first think about the reasoning process in the mind and then provide the answer. The reasoning process and answer should be enclosed within <think> </think> and <answer> </answer> tags, respectively, i.e., <think> reasoning process here </think> <answer> answer here </answer>. 
Given a question and the associated knowledge graph triplets (entity, relation, entity), you are asked to answer the question with these triplets and your own knowledge. 
You can break down the original question into several sub-questions and explore the given knowledge graph to solve them step-by-step. If there are multiple possible answers, choose one as the final answer. 
After thinking, when you finally reach a conclusion, clearly state the answer within <answer> </answer> tags, i.e., <answer> answer here </answer>. 
Question: stadler gtw builds what class of locomotive? 
Knowledge Triplets: Matterhorn Gotthard Bahn ABDeh 4/8, rail.locomotive_class.parent_class, Stadler GTW
Stadler GTW, rail.locomotive_class.subclasses, ZSSK Class 425.95
Stadler GTW, rail.locomotive_class.subclasses, Matterhorn Gotthard Bahn ABDeh 4/8
ZSSK Class 425.95, rail.locomotive_class.parent_class, Stadler GTW
Matterhorn Gotthard Bahn ABDeh 4/10, rail.locomotive_class.parent_class, Stadler GTW
Stadler GTW, rail.locomotive_class.parent_class, Matterhorn Gotthard Bahn ABDeh 4/8
Stadler GTW, rail.locomotive_class.subclasses, Matterhorn Gotthard Bahn ABDeh 4/10
m.0t9ylly, dataworld.gardening_hint.last_referenced_by, ZSSK Class 425.95

Answer: ZSSK Class 425.95
Matterhorn Gotthard Bahn ABDeh 4/8
Matterhorn Gotthard Bahn ABDeh 4/10