What to know now:

1. McMaster is security adviser: Army Gen. H.R. McMaster has accepted the job of national security adviser, one week after Michael Flynn left the job. McMaster is known as a creative thinker, according to The Associated Press,  and was  described by President Donald Trump as "a man of tremendous talent and tremendous experience." McMaster said he looks forward to "doing everything that I can to advance and protect the interests of the American people."

2. But, what did it costs: The AP, Vice Media LLC and Gannett, have asked a judge to force the federal government to divulge how much it paid for an electronic tool to unlock the iPhone of one of the San Bernardino, Calif., terrorist. The three news gathering organizations argued that there was "no adequate justification," to refuse to reveal the cost of the tool the FBI purchased in order to hack into the phone to gather information.

3. Russian ambassador dies: Vitaly Churkin, Russia's ambassador to the United Nations, fell ill suddenly on Monday and died. Churkin collapsed while at work at the Russian mission to the United Nations, was transported to a nearby hospital and died soon after. He was one day short of his 65th birthday. A heart issue is suspected in his death.

4. Journalist Buttner dies: Brenda Buttner, host of the Fox News' Bulls and Bears, died after a battle with cancer. Fox commentator Neil Cavuto, Buttner's colleague, offered a tribute to her Monday on his show, "Your World." "She took stock of life much more than any stock in life. It's what separated her from everyone else in this business. Not just dollars, you see, Brenda had depth," Cavuto said. Buttner was 55.

5. Cassidy has dementia: David Cassidy, the former star of the 70's hit TV show "The Partridge Family," revealed Monday that he is suffering from dementia. Cassidy, 66, has a family history of the disorder. Cassidy said in an interview that both his grandfather and mother suffered from the disease. "I was in denial, but a part of me always knew this was coming," he told People magazine. "I want to focus on what I am, who I am and how I've been without any distractions," Cassidy said in the interview. "I want to love. I want to enjoy life."

And one more

Get your numbers ready, the jackpot for the Powerball lottery has grown to $403 million dollars. No one matched all six numbers Saturday. For the next drawing on Wednesday, the one-time cash payoff is estimated to be at $243.9 million. The $403 million jackpot is the 10th largest in the history of the game. The highest the jackpot ever got was $1.6 billion in January 2016.

In case you missed it

Who saw that coming?