Last night, HBO's "Last Week Tonight" host John Oliver appeared on "The Late Show with Stephen Colbert." The two "Daily Show" alumni traded jokes before they settled on the topic of GOP frontrunner Donald Trump.

Colbert admitted that that he started talking about Trump within 30 seconds of taking "The Late Show" hosting gig over from David Letterman.

"I couldn't give less of a f--k. It's physically impossible," Oliver told Colbert bluntly. "It's the 2016 election and it's 2015 right now, I don't care until we are in the same year as the thing I am supposed to care about."

Oliver joked about the fact that he wasn't even a United States citizen, "taxation without representation," he said.

Oliver told Colbert the reason he did not want to talk about the election on his show was that there were more important issues in the world than presidential candidates like Trump. The two former "Daily Show" correspondents also discussed their mutual respect for Jon Stewart and praised the new host of the Comedy Central show, Trevor Noah. While Colbert throught Noah "crushed it" on his first night as host, Oliver pointed out he was "taking on the impossible" and added that "you can't replace the irreplaceable."