#include<iostream>
#include<iomanip>
using namespace std;
class user{
    protected:
    string usertype;
    string userid;
};
class fitnessapp : public user{
    protected:
    string goal;
    int logs;
    public:
    void calculateaverage(){
        cin>>usertype>>userid;
        cin>>goal>>logs;
        double duration,calories;
        doule totalduration=0,totalcalories=0;
        for(int i=0;i<logs;i++){
            cin>>duration>>calories;
            if(duration<=0 || calories<=0){
                cout<<"Innvalid input";
                return ;
            }
            totalduration += duration;
            totalcalories += calories;
        }
        double average=totalcalories/totalduration;
        cout<<fixed<<setprecision(2)<<average;
    }
};
int main(){
    fitnessapp app;
    app.calculateaverage();
    return 0;
}