#include <iostream>
using namespace std;
class statices{
    private:
    double mean;
    
    public:
    statices(int arr[],int n){
         if(n>0){
            double sum=0;
            for(int i=0;i<n;i++){
                sum+=arr[i];
            }
            mean=sum/n;
        }else{
            mean=0;
            
        }
    }
    statices(const statices&obj){
        mean+obj.mean;
        }
    double getMean(){
        return mean;
    }
    
};
int main()
{
    int n;
    cin>>n;
    if(n<0){
        cout<<"Invalid input";
        return 0;
    }
    int arr[100];
    for(int i=0;i<n;i++){
        cin>>arr[i]
    }
    statices s1(arr,n);
    statices s2=s1;
    cout<<s2.getMean();
    return 0;
}