What is the output

Java

class Main $\{$

public static void swap$($String str$1,$ String str$2)\{$

String holdString;

holdString $=$ str $1$ ;

str$1=$ str$2$;

str$2=$ holdString;

$\}$

public static void main$($String$[]$ args$)\{$

String s$1=$ "Computers";

String s$2=$ "Rock";

swap$($s$1,$ s$2)$;

System.out.println$($s$1+""+$s$2)$;

$\}$

$\}$