#include<iostream>

using namespace std;

class car;

class boat[

private:

int weight;

public:

boat(int weight)

(this->weight=weight;

friend int gettotalweight(boat &b,car &c);

class carf

private:

int weight;

public:

car(int weight)

this->weight=weight;

friend int gettotalweight(boat &b,car &c);

int gettotalweight(boat &b,car &c)

(return b.weight+c.weight;

int main()

boat b(3);

car c(2);

cout<<"總重量是："<<gettotalweight(b,c)<<endl;

return 0;