Consider the following $C++$ program, what is the output generated in the main function?

float fun $($int& first, float& third$)$ f

int second $=1$;

first $=$ first $+$ second;

third $=$ second $+$ third;

return first;

$\}$

int main$()$

float $w=2,z$;

int $i=4$;

$z=$fun$(i,w)+w-2**i$;

return $0$ ;