#include <iostream.h>

double media() {
    int i,n;  
    cin >> n;
    float*  x = new float[n];
    float *y = x;//y punta a x[0]
    double sum;

    sum = 0;
    for ( i = 0; i < n; i++) {
        cin >> x[i] ;
        sum += *y++;
    }
    return sum/n;
    delete [] x;
}


int main() {
  cout << media()<<endl;
  return 0;
}