What is the output of this Java program?

class Driver $\{$

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

int $a\frac{?}{b}=ar(2)$

int $b=f(a)$;

System,out.print$($b$)$;

$\}$

static int foo$($int a$)\{$

$a=-1$;

return $a$;

$\}$

static int bar$($int a$)\{$

System.out.print$($a$)$;

return $a+3$;

$\}$

$\}$