How to make a Gui show up if the player hasn't moved the mouse for ten seconds?

Here is what I did. I made comments so you know what each part does. Also, you can make the while loop run under a certain condition if you did not know. This will stop a lot of lag im pretty sure. Also, you can use the Idle event that detects if the mouse has not moved, or pressed a button. The debounces are just so that the wait functions actually have a use, and that it counts in seconds, not milliseconds.

local times = 10
local player = game.Players.LocalPlayer
local debounce = false
local debounce2 = false
game.Players.LocalPlayer:GetMouse().Idle:connect(function() --Fires when the mouse is idle and when times is not 0.
    if debounce == false and times ~= 0 then
        debounce = true
        wait(1)
        times = times - 1
        print("Screenz:".. times)
        debounce = false
        debounce2 = false --Makes the movement detecting function run again since the debounce is false.
    end
end)

game.Players.LocalPlayer:GetMouse().Move:connect(function() --Fires when the mouse is moving and when times is not 10
    if debounce2 == false and times ~= 10 then
        debounce2 = true
        times = 10
        player.PlayerGui.Screensaver.Main.Visible = false
    end
end)

while times == 0 do --Fires when times is 0.
    wait()
    player.PlayerGui.Screensaver.Main.Visible = true
    break --Breaks the loop so it reduces lag.
end

First let's create a function that will run when they haven't moved in 10 seconds and debounce variable

local d = true

function runthis()
    print('hi')
end

Next let's create a variable for the seconds and mouse Move event

local lasttime = 0
local mouse = game.Players.LocalPlayer:GetMouse()

mouse.Move:connect(function()
    lasttime=0
    d=true
end)

now for the changing the lasttime variable and check if its over 10

while true do
    if lasttime>10 then
        d=false
        runthis()
    end
    if d==true then
        lasttime=lasttime+1
        wait(1)
    end
end

Let's put it together

local d = true

function runthis()
    print('hi')
end

local lasttime = 0
local mouse = game.Players.LocalPlayer:GetMouse()

mouse.Move:connect(function()
    lasttime=0
    d=true
end)

while true do
    if lasttime>10 then
        d=false
        runthis()
    end
    if d==true then
        lasttime=lasttime+1
        wait(1)
    end
end

local player = game.Players.LocalPlayer
local mouse = player:GetMouse()
local move = tick()

mouse.Move:Connect(function()
    move = tick()
end)

while true do
    wait()
    if tick() - move >= 10 then
        print("10 seconds")
    -- tried to add break() here, but it wont run it again when the player moves the mouse, after 10 seconds
    end
end