Teacher:In this task, you are given a paragraph, event and an entity. The event is part of the given paragraph and it changes the state of the entity. Your task is to classify the state of the entity into three classes: 1) not exist, 2) unknown location and 3) known location. "not exist" means the entity doesn't exist in that state anymore. "unknown location" means the entity exists in that state but location is unknown. "known location" means the entity exists and location is known. 
Teacher: Now, understand the problem? Solve this instance:  "process paragraph : : Coal is burned at a furnace. The resulting heat energy is used to heat water. The heated water is turned into steam. The steam drives a generator. Electricity is produced. ", "event : The resulting heat energy is used to heat water.", "entity : coal" 
Student:
 not exist 