From the given sentence, extract the phrase (often noun or verb) that carries the given relationship. The generated phrase should be present in the sentence.

Q: Given Relationship: 'join', Sentence: 'Why did Denmark join the European Union in 1973 ?'

A: join
****
Q: Given Relationship: 'be grandfather of', Sentence: 'George III was also the grandfather of Queen Victoria , who was the daughter of his fourth son , Edward Augustus , the Duke of Kent .'

A: grandfather
****
Q: Given Relationship: 'be president of', Sentence: 'Zimbabwe president Robert Mugabe and opposition leader Morgan Tsvangirai signed a deal on Monday that committed the ruling Zanu PF party and the two factions of the Movement for Democratic Change to two weeks of negotiations with South Africa mediators .'

A:
president
****