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
while tux>0:
    tux-=1
    pur=int(input())
    foo+=pur
    bar+=1
    if max(foo*quz,bar*baz) == foo*quz:
        baz=foo
        quz=bar
print(baz/quz)
