n = int(input())
a = list(map(float, input().split()))
s = 0
for i in range(n):
s += a[i]
avg = s / n
print(f"{avg:.2f}")
biA9IGludChpbnB1dCgpKQphID0gbGlzdChtYXAoZmxvYXQsIGlucHV0KCkuc3BsaXQoKSkpCnMgPSAwCmZvciBpIGluIHJhbmdlKG4pOgogICAgcyArPSBhW2ldCmF2ZyA9IHMgLyBuCnByaW50KGYie2F2ZzouMmZ9Iik=