Definition: You will be given three sentences. Read them, then identify a noun phrase (person, place, or thing) or event that is shared between all three sentences. As the output, write the span of the text corresponding to that phrase in each sentence. Keep the order of the sentences, that is, your answer should look like: 1: *a phras from sentence 1e* 2: *a phras from sentence 2* 3: *a phrase from sentence 3*
Input: 1: But it would be an extraordinary step and certainly not a foregone conclusion that the U.S . would attempt to board an Iranian ship if it entered Yemeni waters , U.S . officials said . 2: U.S . warships from the carrier group of the Roosevelt are joining allied vessels from Saudi Arabia , Egypt and other partner nations prepared to intercept a convoy of seven to nine Iranian vessels believed headed for Yemen . 3: U.S. , allied ships prepared to intercept Iranian vessel if they enter Yemen 's waters .

1: attempt to board an Iranian ship 2: intercept a convoy of seven to nine Iranian vessels 3: intercept Iranian vessel