#include<iostream>
#include<iomanip>
using namespace std;
int main()
{
   int a,count=0,arr2;
   cin>>a;
   float arr[a],sum=0;
   for(int i=0;i<a;i++)
   {
       if(cin>>arr[i])
       {
       count+=1;
       sum+=arr[i]
       }
       else
       {
           break;
       }
       
   }
   
   if(count!=a)
   {
      
       cout<<"Incomplete Data";
       return 0;
   }
   
       for(int i=0;i<a;i++)
       {
           if(arr[i]<0)
           {
           cout<<"Invalid Rainfall";
           return 0;
           }
           

   }
   
      cout<<fixed<<setprecision(2)<<sum; 
      
  
   
}