#include <bits/stdc++.h>
using namespace std;
long long Set(long long n, long long pos) { return (n = n | 1 << pos); }
long long reset(long long N, long long pos) { return N = N & ~(1 << pos); }
bool check(long long N, long long pos) { return (bool)(N & (1 << pos)); }
long long pow(long long a, long long b, long long mod) {
  long long x = 1, y = a;
  while (b > 0) {
    if (b % 2 == 1) {
      x = (x * y);
      if (x > mod) x %= mod;
    }
    y = (y * y);
    if (y > mod) y %= mod;
    b /= 2;
  }
  return x;
}
long long modInverse(long long a, long long m) { return pow(a, m - 2, m); }
int arr[(long long)1e6 + 1];
int main() {
  int n;
  while (cin >> n) {
    double tot = 0;
    for (int i = 0; i < n; i++) cin >> arr[i], tot += arr[i];
    tot /= (double)(n);
    cout << setprecision(10) << tot << endl;
  }
}
