#include<iostream>
#include<iomanip>
using namespace std;
class Rainfall{
    static float total;
    public:
    static void addRain(float r)
    {total +=r;}
    static float getTotal()
    {return total;}
};
float Rainfall::total = 0;
int main(){
    int n;
    if(!(cin>>n)) return 0;
    for (int i=0;i<n;i++){
        float r;
        if(!(cin>>r)){
            cout<<"Incomplete Data"<<endl;
            return 0;
        }
        if(r<0){
            cout<<"Invalid Rainfall"<<endl;
            return 0;
            
        }
        Rainfall::addRain(r);
    }
    cout<<fixed<<setprecision(2)<,Rainfall::getTotal()<<endl;
    return 0;
}