Test $1(8$ points$).$ Show the output of the following program:

public class Testo$1\{$

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

char $x=\text{'}a\text{'}$;

char $y={?}^{\text{'}}{c}^{\text{'}}$;

System.out.println$(++$x$)$;

System.out.println $(y++)$;

System.out.println$(x-y$;

$\}$

$\}$