#include <iostream>
using namespace std;
class A
{
private:
int n,sum;
public:
A()
{
n=4;
}
A(int nn)
{
n=nn;
}
void input()
{
cout<<"input n:";
cin>>n;
}
void output()
{
cout<<"n="<<n<<endl;
cout<<"sum="<<sum<<endl;
}
A o
{
private:
int n,sum;
public:
A()
{
n=4;
}
A(int nn)
{
n=nn;
}
void input()
{
cout<<"input n:";
cin>>n;
}
void output()
{
cout<<"n="<<n<<endl;
cout<<"sum="<<sum<<endl;
}
A o