#include <iostream>
#include<iomanip>
using namespace std;
struct calavg{
    int *arr;
    int a;
}
float average(calavg *s)
{
    int sum=0;
     for(int i=0;i<s->a;i++)
     {
        sum+=s->arr[i];
     }
     float avg=(float)sum/s->x;
     return avg;
}
int main() {
     calavg s;
     cin>>s.a;
     s.arr=new int[s.a];
     for(int i=0;i<s.a;i++)
     {
         cin>>s.arr[i];
     }
     cout<<fixed<<setprecision(2)<<average(&s);
     
}