(CNN)Happy (really cold) New Year and welcome back to reality in 2018. If you ate and partied your way through the holidays, you may have missed some newsworthy moments. Here's a quick rundown to start the first week of the year smart:
Start your week smart: These are the stories to know
-- President Trump's first tweet of the new year took a swipe at Pakistan.
-- At least 12 people died in Iran as a fifth day of protests swept the country. President Rouhani called for calm and downplayed the unrest.
-- In his annual New Year's Day address, North Korean leader Kim Jong Un held out a rare olive branch to South Korea.
-- A New Jersey teen is in custody after four people, including his parents and his sister, were killed on New Year's Eve.
-- A New York family of five are among 12 people killed in a small plane crash in Costa Rica.
-- The Colorado gunman who on Sunday killed a deputy in a Denver suburb was an Iraq deployment veteran.
-- There's still a (very slim) chance to win both the Powerball and Mega Millions prizes, which now have reached a combined total of $783 million.
-- New York City's deadliest fire since 1990 was started by a 3-year-old playing with a stove.
-- Californians lined up to buy pot after the state became the latest to legalize recreational marijuana.
-- Reese Witherspoon, Shonda Rhimes and Meryl Streep are among the powerful women in the anti-harassment group Time's Up.
-- Someone forgot Mariah's hot tea. And the first meme of the year was born.