class to calculate marks of maths

#include<iostream.h>
#include<conio.h>
class A
{
public:
int a;
class B
{
public:
int b;
void show()
{
cout<<"2nd class\n";
cout<<"enter value of b \n";
cin>>b;
}
};
B bj;
void put()
{
cout<<"1st class\n";
cout<<"enter value of a \n";
void show();
}
}aj;
void main()
{
clrscr();
aj.put();
bj.show();
getch();
}#include<iostream.h>
#include<conio.h>
class maths
{
private:
int a[100];
int c;
public:
void input()
{
cout<<"enter the marks of math\n";
for(int j=0;j<=50;j++)
{
cin>>a[j];
}
bj.input(a);
}



class chem
{
private:
int sum[100];
int b[100];
int d[100];

public:
void input(int q[100])
    {
 for(int i=0;i<=50;i++)
 {
 d[i]=q[i];
 }

cout<<"enter marks of chem \n";
for(int i=0;i<=50;i++)
{
cin>>b[i];
sum[i]=d[i]+b[i];

}
for(int i=0;i<=50;i++)
{
cout<<sum[i];

}

cout<<"average\n"<<sum[]/2
    }

}bj;
}aj;
void main()
{
clrscr();
aj.input();
getch();
}