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: 'Tomorrow Barack Obama will become president of the United States .'

Output: president

Input: Consider Input: Given Relationship: 'present at', Sentence: 'Paper presented at Annual Conflict Research Society Conference , University of Ulster Magee Campus , Northern Ireland , 1-3 September 2004 .'

Output: presented

Input: Consider Input: Given Relationship: 'be author of', Sentence: 'Mark Bowden , author of Black Hawk Down , takes a more in-depth look at the 1958 NFL Championship game between the Baltimore Colts and New York Giants , dubbed The Greatest Game Ever Played .'
Output: author