How Do I Do My PlayerNum script?

I mean, I know how to do them, it's- just-well I'll show you.

function waitForPlayers(minimum)
    repeat
        Game.Players.PlayerAdded:wait() 
script.Parent.Text = "4 Players Needed For The Game To Start..."    
until Game.Players.NumPlayers >= minimum 
end
 
waitForPlayers(4)
for i = 8,0,-1 do
    script.Parent.Text = tostring(i)
  Game.Workspace.Tick:Play()
wait(1)
end

This script is under a SurfaceGui in a Part. The word 'Tick' is the sound that will be playing in my game.

The part that I'm having a hard time working on is when your playing the game when someone leaves and there are only 3 players left it goes back to the waiting time.

Can someone help me please?