The number by the red icon at the top of the Home screen is your lives.
Lives represent the number of times you can play puzzle levels.
One life is restored every 30 minutes, and you lose one every time you fail a level.
The maximum number of lives is 5.
However, if you have purchased a Premium Pass, the maximum number of lives for the duration is 8.
In addition, if you receive a life request in your team, you may stock up to a maximum of 5 lives beyond the limit.