#include <bits/stdc++.h>
using namespace std;
int sum, N;
int main() {
  scanf("%d", &N);
  for (int i = 1, temp; i <= N; i++) {
    scanf("%d", &temp);
    sum += temp;
  }
  printf("%.9lf\n", double(sum) / double(N));
  return 0;
}
