#include <bits/stdc++.h>
int main(void) {
  int n;
  scanf("%d", &n);
  double p[n];
  double prcnt, sum = 0;
  for (int i = 0; i < n; i++) {
    scanf("%lf", &p[i]);
    p[i] = p[i] / 100;
    sum = sum + p[i];
  }
  prcnt = (sum / n) * 100;
  printf("%0.12f", prcnt);
  return 0;
}
