#include<iostream>
#include<iomanip>
using namespace std;
class ra
{
    public:
    static double t;
    static void cal()
    {
        int n;
        if(!(cin>>n))
        {
            cont<<"Incomplete Data";
            return;
        }
        double value;
        for(int i=0;i<n;i++)
        {
            if(!(cin>>value))
            {
                cout<<"Incomplete Data";
                return;
            }
            if(value<0)
            {
                cout << "Invalid Rainfall";
                return;
            }
            t+=value;
        }
        cout<<fixed<<setprecision(2)<<t;
    }
};
double ra::t=0;
int main()
{
    ra::cal();
    return 0;
}