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).
tux = int(input())
foo = 0
bar = 0
baz = 0
quz = 1
for i in range(tux):
    pur = int(input())
    foo += pur
    bar += 1
    if foo * quz > baz * bar:
        baz = foo
        quz = bar
print(baz / quz)