#include <bits/stdc++.h>
double a, b;
double c, suma;
int main() {
  scanf("%lf", &a);
  for (int i = 0; i < a; i++) {
    scanf("%lf", &b);
    suma = suma + b;
  }
  c = suma / a;
  printf("%0.12lf", c);
}
