// editor1
#include<iostream>
using namespace std;
class journey{
    public:
    double d,s;
    journey(double s,double d):d(d),s(s){}
    double time() {
        return d/s;
    }
};
class car_journey:public journey{
    public:
    carjourney(double d,double s):journey(d,s){}
    
};
class bike_journey:public journey{
    public:
    bikejourney(double d,double s):journey(d,s){}
    
};
class train_journey:public journey{
    public:
trainjourney(double d,double s):journey(d,s){}
    
};
int main(){
    string type;
    double d,s;
    cin>>type>>d>>s;;
    if (type=="car") cout<<car journey(d,s).time();
    if (type=="bike")cout<<bike journey(d,s).time();
    if (type=="train")cout<<train journey(d,s).time();
    return 0;
    
}