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.

Input: Consider Input: Given Relationship: 'be president of', Sentence: 'When Barack Obama became the 44th president of United States , there was a sense of ecstasy , joy and relief in virtually every country of the world , except in Pakistan , Iraq and Afghanistan .'

Output: president

Input: Consider Input: Given Relationship: 'appoint', Sentence: 'The Commission appoints the Director and approves the operating and capital budgets submitted to the Governor and Legislature .'

Output: appoints

Input: Consider Input: Given Relationship: 'be mayor of', Sentence: 'London 's mayor Boris Johnson launched a furious verbal attack on Labour MP Keith Vaz , it is claimed .'
Output: mayor