#include <iostream>
using namespace std;

class Statistics
{
    public:
    double mean;
    
    Statistics(int arr[], int n)
    {
        int sum = 0;
        for(int 1=0; i<n; i++)
        {
            sum +=arr[i];
        }
        mean = (double)sum/n;
    }
    
    Statistics(const Statistics &s)
    {
        mean = s.mean;
    }
};

int main()
{
    int n;
    cin>>n;
    
    if(nn<0)
    {
        cout<<"Invalid input";
        return 0;
    }
    
    int arr[10];
    for(int i =0; i<n; i++)
    {
        cin>>arr[i];
    }
    
    Statistics s1(arr,n);
    Statistics s2(s1);
    
    cout<<s2.mean;
    return 0;
}