What is the output of the following program?

#include

using namespace std;

class Mountain

$\{$

public:

double get$\_$height$()$ const;

Mountain$()$;

Mountain$($double new$\_$height$)$;

private:

double height;

$\}$;

Mountain::Mountain$()$

$\{$

height $=0$;

$\}$

Mountain::Mountain$($double new$\_$height$)$

$\{$

height $=$ new$\_$height;

$\}$

double Mountain::get$\_$height$()$ const

$\{$

return height;

$\}$

int main$()$

$\{$

Mountain cth$1$;

Mountain cth$2(15000)$;

double total$\_$height $=0$;

total$\_$height $=$ cth$1.$get$\_$height$()+$ cth$2.$get$\_$height$()$;

cout $<<$ total$\_$height $<<$ endl;

return $0$;