What happens when the following program is executed by an Arduino?

$($If in doubt, type it in Tinkercad and see what happens$)$

$1$ int led $=9$;

$2\}\backslash$mathrm$\{$ int brightness $=0$;

$3$ int Amount $=5$

$4$

$5$ void setup$()\{$pinMode$($led$,$ OUTPUT$)$;$\}$

$6$

$7$ void loop$()$

$8\{$

analogWrite$($led$,$ brightness$)$;

brightness $=$ brightness $+$ Amount;

if $($brightness brightness $>=255)$

$\{$

Amount $=-$Amount

$\}$

delay$(30)$;

$\}$