#include <iostream>
#include <string>
#include <iomanip>
using namespace std;
class User{
    protected:
    string usertype;
    string userID;
    public:
    void getuserinfo(){
        cin>>usertype>>userID;}};
class Workout : protected User{
    protected:
    string goal;
    int logs;
    double totalcalories=0;
    double totalduration=0;
    public:
    void inputUser(){
        getuserinfo();}
    void getworkoutData(){
        cin>>goal>>logs;
        for(int i=0;i<logs;i++){
            double duration,calories;
            cin>>duration>>calories;
            if(duration<=0 || calories<=0){
                cout<<"Invalid input";
                exit(0);}
            totalduration += duration;
            totalcalories += calories;}}
    void calculateAverage(){
        double avg=totalcalories/totalduration;
        cout<<fixed<<setprecision(2)<<avg;
    }
};
int main(){
    Workout m;
    m.inputUser();
    m.getworkoutData();
    m.calculateAverage();
    return 0;
}
            
        
    
}