#include<iostream>
#include<vector>
#include<iomanip>
using namespace std;
int main()
class statistics{
   private:
    double mean;
    public:
    statistics(int n, const vector<int>& data){
        if(n==0){
            mean =0.0;
            return;
        }
        double sum=0;
        for(int val : data){
            sum +=val;
        }
        mean=sum/n;
    }
    statistics(count statistics&other){
        this->mean = other.mean;
    }
    void displayMean(){
        cout<<mean<<endl;
    }
};
int main(){
    int n;
    if(!(cin>>n)) return 0;
    if (n<0) {
        cout<<<" Invalid input"<<endl;
        return 0;
    }
    vector<int> database(n);
    for(int i=0;i<n;i++){
        cin>>database[i];
    }
    statistics originalsstats(n,database);
    statistics copidstats=originalstats;
    copiedstats.displayMean();
    return 0;
}