What is the program's output?

public class output $\{$

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

double a;

a $=$ Math.sqrt$(16\mathrm{.}00)$;

$//$ This will output $2$ decimal places.

System.out.printf$("\%\mathrm{.}2$f$",$ a$)$;

$\}$

$\}$