#include <bits/stdc++.h>
int main() {
  int n, x, i;
  float avg, sum = 0;
  scanf("%d", &n);
  for (i = 1; i <= n; i++) {
    scanf("%d", &x);
    sum = sum + x;
  }
  avg = sum / n;
  printf("%.12f\n", avg);
}
