#include <bits/stdc++.h>
int main() {
  int n, i, a, s;
  double sum, s1;
  while (scanf("%d", &n) == 1) {
    s = 0;
    for (i = 0; i < n; i++) {
      scanf("%d", &a);
      s += a;
    }
    s1 = s * 1.0 / 100;
    printf("%0.12f\n", s1 / n * 100);
  }
  return 0;
}
