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=FOO+PUR
  BAR=BAR+1
  if FOO*QUZ>BAZ*BAR:
    BAZ=FOO
    QUZ=BAR
print(BAZ/QUZ)