#include <iostream.h>
#include <conio.h>
class triangle {
     public:
       triangle();
    void  input();
    void  calculate();
    void  print();
     private:
     float hieght;
     float base;
     float cal;
      };
       triangle::triangle( )
      {
      hieght=1;
      base=1;
      }
    void  triangle::input()
      {
       cout<<"Enter..:";
       cin>>hieght>>base;

       }
    void   triangle :: calculate()
       {
     cal=(hieght*base)/2;
       }
    void   triangle :: print()
       {

       cout<<cal<<endl;
       }
      int main ()
      {
       clrscr();
       triangle t;
      t.calculate();
      t.print();
      t.input();
      t.calculate();
      t.print();
      getch();
      return 0;
      }