#include <bits/stdc++.h>
int main() {
  int n;
  scanf("%d", &n);
  float a[n];
  float sum = 0;
  int total = 100 * n;
  for (int i = 0; i < n; i++) {
    scanf("%f", &a[i]);
  }
  for (int i = 0; i < n; i++) {
    sum = sum + a[i];
  }
  printf("%.12f\n", (sum / total) * 100);
  return 0;
}
