TASK DEFINITION: In this task, you're given an open-domain question. Your task is to provide an answer to the given question. There is only one unique answer for each question. Your answer should be short, and refer to an entity, date, number, etc. Do not put your answer in the context of a sentence.
PROBLEM: Who presides over any impeachment trial of the president of the united states?

SOLUTION: Chief Justice of the United States

PROBLEM: Which unit is used to measure mass in the metric system?

SOLUTION: kilogramme

PROBLEM: What capital city is 400 miles east of algiers algeria?

SOLUTION:
El Oued