You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Greece

Context:
Legislative powers are exercised by a 300-member elective unicameral Parliament. Statutes passed by the Parliament are promulgated by the President of the Republic. Parliamentary elections are held every four years, but the President of the Republic is obliged to dissolve the Parliament earlier on the proposal of the Cabinet, in view of dealing with a national issue of exceptional importance. The President is also obliged to dissolve the Parliament earlier, if the opposition manages to pass a motion of no confidence.

Question:
How often are elections help for parliament?

every four years