#include<iostream>
#include<iomanip>

using namespace std;
int main(){
    string s;cin>>s;
    double a,b;
    if(s=="circle"){
        cin>>a;
        if(a>0){cout<<"Invalid input";return 0;}
        cout<<fixed<<setprecison(2)<<3.14*a*a;
    }
    else if(s=="rectangle"){
        cin>>a>>b;
        if(a<=0||b<=0){cout<<"Invalid input";return 0;}
        cout<<fixed<<setprecison(2)<<a*b;
    }
    else cout<<"Invalid input";
}