The function $f(x,y)$ satisfies the Laplace equation $$\bigtriangledown^{2}f(x,y) = 0$$

on a circular domain of radius $r=1$ with its center at point $P$ with coordinates

$x=0, y=0.$ The value of this function on the circular boundary of this domain

is equal to $3.$

The numerical value of $f(0,0)$ is:

1. $0$
2. $2$
3. $3$
4. $1$