# boj, 1546 : 평균, python3
import sys
N = int(sys.stdin.readline())
score = list(map(int,sys.stdin.readline().split()))
result = []
for i in range(N):
if score[i] <= max(score):
result.append(score[i]/max(score)*100)
print(sum(result)/N)
https://www.acmicpc.net/problem/1546