#include<iostream>
using namespace std;
class shape {
    public:
    void circle(){
        double area,d1,d2;
        string shapee;
       
        cin>>shapee;
        if (shapee == "circle" || shapee=="rectangle"){
            if (shapee == "circle"){
                cin>>d1;
                if(d1>=1 && d1<=100){
                    area = 3.1416 * (d1*d1);
                    cout<<area;
                }
                }
            else{
                cin>>d1>>d2;
                if((d1&&d2)>=1 && (d1&&d2)<=100){
                    area = d1*d2;
                    cout<<fixed<<setprecision(2)<<area;
                }
                }
        }
        else{
        cout<<"Invalid shape type";
        }

       
    }
    
    
};
int main(){
    
    shape a;
    a.circle();
    
    
}