The input contains between 1 and 10 lines, *i*-th line contains an integer number *x*<sub class="lower-index">*i*</sub> (0 ≤ *x*<sub class="lower-index">*i*</sub> ≤ 9).
numbers = []
highest = 0
for _ in range(int(input())):
	numbers.append(int(input()))
	if highest < sum(numbers)/len(numbers): highest = sum(numbers)/len(numbers)
print(highest)

"""
FOO = sum(input)
BAR = number input
BAZ = 0
QUZ = 0
#BOTH SAEM ( 
	BIGGR OF (
		(PRODUKT OF FOO AN QUZ) 
		AN (PRODUKT OF BAR BAZ)
	) 
	AN (PRODUKT OF FOO AN QUZ))"""