#include <iostream.h>

double media(float *y, int n) {
    int i;  
    double sum;

    sum = 0;
    for ( i = 0; i < n; i++) 
        sum += *y++;
    
    return sum/n;
}


int main() {
    int i,n;
    cin >> n;
    float*  x = new float[n];
    for ( i = 0; i < n; i++) 
        cin >> x[i] ;
    cout << media(x,n)<<endl;
    delete [] x;
  return 0;
}