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, bar, baz, quz = 0, 0, 0, 1

for _ in range(tux):
    foo += int(input())
    bar += 1

    if foo * quz >= bar * baz:
        baz, quz = foo, bar

print(baz / quz)