#include <bits/stdc++.h>
int main() {
  int a, b, c, d, e, n, i, j, sum = 0;
  double ans;
  scanf("%d", &n);
  for (i = 0; i < n; i++) {
    scanf("%d", &a);
    sum = sum + a;
  }
  ans = (double)sum / n;
  printf("%lf\n", ans);
}
