write an program to calculate simple interest using to construct in c++

#include<iostram.h>
#include<conio.h>
       class si
             { private: int p,t,r,si=0;
                public:interest()
     {cout<<"enter any value of p,t,r,:";
      cin>>p>>t>>r;
        si=p*t*r/100;
cout<<"si="<<si;
    }
};
void main()
  { si.s
    getch();
     }vvvvv