// editor2
#include <iostream>
#include <iomanip>
using namespace std;
class Rainfall{
    private: 
    static float total;
    
    public:
    static void addRainfall(float value){
        total+=value;
    }
    
    static float getTotal(){
        return total;
    }
};

float Rainfall::total = 0;

int main(){
    int n;
    
    if(!(cin>>n)){
        cout<<"Incomplete Data";
        return 0;
    }
    
    float value
    
    for(int i=0; i<n; i++){
    
    if(!(cin>>value)){
        cout<<"Incomplete Data";
        return 0;
    }
    
    if(value<0){
        cout<<"Invalid Rainfall";
        return 0;
    }
    
    Rainfall::addRainfall(value);
    
}

cout<<fixed<<setprecision(2)<<Rainfall:getTotal();

return 0;
}