#include<iostream>
#include<iomanip>
#include<cmath>
using namespace std;

int main(){
    string shapType;
    cin>>shapType;
    
    const double PT=3.14159;
    
    if (shapType == "circle"){
        double radius;
        cin>>radius;
        
        if(radius<=0){
            cout<<"Invalid input";
        }else{
            double area = PT * radius * radius;
            cout<<fixed<<setprecision(2)<<area;
        }
        }else if (shapeType == "rectangle"){
        double width,height;
        cin>> width>>height;
        
        if(width<=0||height<=0){
            cout<<"Invalid input";
        }else{
            double area =width*height;
            cout<<fixed<<setprecision(2)<<area;
    }
}
else {
    cout<<"Invalid input";
}
return 0;
}