#과목 개수 입력
n = int(input())
#과목 점수들 입력
a = list(map(int, input().split()))
#내림차순으로 정리
b = sorted(a)
#계산
for l in range(n):
if int(b[l]) != int(max(b)):
b[l] = (int(b[l])/int(max(b)))*100
else:
b[n-1] = 100
#출력
print(sum(b)/n)
I+qzvOuqqSDqsJzsiJgg7J6F66ClCm4gPSBpbnQoaW5wdXQoKSkKI+qzvOuqqSDsoJDsiJjrk6Qg7J6F66ClCmEgPSBsaXN0KG1hcChpbnQsIGlucHV0KCkuc3BsaXQoKSkpCiPrgrTrprzssKjsiJzsnLzroZwg7KCV66asCmIgPSBzb3J0ZWQoYSkKI+qzhOyCsApmb3IgbCBpbiByYW5nZShuKToKICAgIGlmIGludChiW2xdKSAhPSBpbnQobWF4KGIpKToKICAgICAgICBiW2xdID0gKGludChiW2xdKS9pbnQobWF4KGIpKSkqMTAwCiAgICBlbHNlOgogICAgICAgIGJbbi0xXSA9IDEwMAoj7Lac66ClCnByaW50KHN1bShiKS9uKQo=