Package for this problem was not updated by the problem writer or Codeforces administration after we’ve upgraded the judging servers. To adjust the time limit constraint, solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then value 800 ms will be displayed and used to determine the verdict.

Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ACM-ICPC mode for virtual contests.
If you've seen these problems, a virtual contest is not for you - solve these problems in the archive.
If you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.
Never use someone else's code, read the tutorials or communicate with other person during a virtual contest.

No tag edit access

C. WTF?

time limit per test

2 secondsmemory limit per test

256 megabytesinput

standard inputoutput

standard output

HAI

I HAS A TUX

GIMMEH TUX

I HAS A FOO ITS 0

I HAS A BAR ITS 0

I HAS A BAZ ITS 0

I HAS A QUZ ITS 1

TUX IS NOW A NUMBR

IM IN YR LOOP NERFIN YR TUX TIL BOTH SAEM TUX AN 0

I HAS A PUR

GIMMEH PUR

PUR IS NOW A NUMBR

FOO R SUM OF FOO AN PUR

BAR R SUM OF BAR AN 1

BOTH SAEM BIGGR OF PRODUKT OF FOO AN QUZ AN PRODUKT OF BAR BAZ AN PRODUKT OF FOO AN QUZ

O RLY?

YA RLY

BAZ R FOO

QUZ R BAR

OIC

IM OUTTA YR LOOP

BAZ IS NOW A NUMBAR

VISIBLE SMOOSH QUOSHUNT OF BAZ QUZ

KTHXBYE

Input

The input contains between 1 and 10 lines, *i*-th line contains an integer number *x*_{i} (0 ≤ *x*_{i} ≤ 9).

Output

Output a single real number. The answer is considered to be correct if its absolute or relative error does not exceed 10^{ - 4}.

Examples

Input

3

0

1

1

Output

0.666667

Codeforces (c) Copyright 2010-2019 Mike Mirzayanov

The only programming contests Web 2.0 platform

Server time: Jul/19/2019 12:07:05 (g1).

Desktop version, switch to mobile version.

Supported by

User lists

Name |
---|