#include <bits/stdc++.h>
int main() {
  int n, i, cnt = 0;
  float y;
  scanf("%d", &n);
  int p[n];
  for (i = 1; i <= n; i++) {
    scanf("%d", &p[i]);
    cnt += p[i];
  }
  y = (float)cnt / (float)n;
  printf("%f", y);
  return 0;
}
