A sequence of real numbers is defined recursively as follows: and are positive real numbers, and

A sequence of real numbers $(x_n)$  is defined recursively as follows: $x_0=a$  and $x_1=b$  are positive real numbers, and

$x_{n + 2} = \frac{1 + x_{n + 1}}{x_n}$
for n = 0,1,2...  . Find the value of  $​​​​x_{2012}$, in terms of a and b .