#include <bits/stdc++.h>
int main() {
  int turn = 0;
  scanf("%d", &turn);
  int a[101];
  for (int i = 0; i < turn; i++) {
    scanf("%d", &a[i]);
  }
  float calc = 0;
  for (int i = 0; i < turn; i++) {
    calc = calc + a[i];
  }
  calc /= turn;
  printf("%f", calc);
  return 0;
}
