Q: 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.
Given Relationship: 'be president of', Sentence: 'Barack Obama will be sworn as America 's first black president Tuesday under the tightest security ever , shielded by a new , heavily armoured Cadillac limousine , bullet-resistant glass , fighter planes overhead and Secret Service SWAT teams toting automatic weapons .'
A:
president