#include<iostream>
#include<vector>
#include<numeric>
#include<iomanip>
using namespace std;
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(const Statistics& other){
        this->mean = other.mean;
    }
    void displayMean() const{
        if (mean == (int)mean){
            cout<<(int)mean<<endl;
        }
        else{
            cout<<fixed<<setprecision(2)
        }
    }
};
int main()
{
    int n;
    if(!(cin>> n))return 0;
    if(n < 0){
        cout<<"Invalid input"<<endl;
        return 0;
    }
    vector<int> data(n);
    for(int i=0;i<n;++i){
        cin>>date[i];
    }
    Statistics obj1(n,data);
    Statistics obj2 = obj;
    obj2.displayMean();
    return 0;
}