C++ program to swap numbers between two objects of different class

 /* c++ program to swap no between two objects of diff class */

#include<iostream>
using namespace std;
class A
{
public:

 int num1;

 void input()
 {
 cout<<"\nenter the number:";
 cin>>num1;
 }
 void display()
 {
 cout<<num1<<endl;
 }
friend class B;
};
class B
{
public:

 int num2;

 void input()
{
 cout<<"\nenter the second number:";
 cin>>num2;
}
void display()
{
cout<<num2<<endl;
}
friend class A;
};
void swapping(A &A1,B &B1)
{
int temp;
temp=A1.num1;
A1.num1=B1.num2;
B1.num2=temp;
}
int main()
{
A A11;
B B11;
A11.input();
B11.input();
cout<<"number before swapping:";
A11.display();
B11.display();
swapping(A11,B11);
cout<<"number after swapping:";
A11.display();
B11.display();
return 0;
}