King of Thieves

题意翻译

给定一段路，其中有陷阱和平台，如果踩到陷阱就算输。在平台上可以跳跃到另一个向前的平台。如果从平台 $i$ 连续跳四次，且每次跳跃长度相等，则称为这是一次好的跳跃。 现在给定一个长度为 $n$ 的字符串 $s$，其中 `.` 表示陷阱，`*` 表示平台，输出 $s$ 有无可能出现一次好的跳跃。

题目描述

In this problem you will meet the simplified model of game King of Thieves. In a new ZeptoLab game called "King of Thieves" your aim is to reach a chest with gold by controlling your character, avoiding traps and obstacles on your way. An interesting feature of the game is that you can design your own levels that will be available to other players. Let's consider the following simple design of a level. A dungeon consists of $ n $ segments located at a same vertical level, each segment is either a platform that character can stand on, or a pit with a trap that makes player lose if he falls into it. All segments have the same length, platforms on the scheme of the level are represented as '\*' and pits are represented as '.'. One of things that affects speedrun characteristics of the level is a possibility to perform a series of consecutive jumps of the same length. More formally, when the character is on the platform number $ i_{1} $ , he can make a sequence of jumps through the platforms $ i_{1}<i_{2}<...<i_{k} $ , if $ i_{2}-i_{1}=i_{3}-i_{2}=...=i_{k}-i_{k-1} $ . Of course, all segments $ i_{1},i_{2},...\ i_{k} $ should be exactly the platforms, not pits. Let's call a level to be good if you can perform a sequence of four jumps of the same length or in the other words there must be a sequence $ i_{1},i_{2},...,i_{5} $ , consisting of five platforms so that the intervals between consecutive platforms are of the same length. Given the scheme of the level, check if it is good.

输入输出格式

输入格式

The first line contains integer $ n $ ( $ 1<=n<=100 $ ) — the number of segments on the level. Next line contains the scheme of the level represented as a string of $ n $ characters '\*' and '.'.

输出格式

If the level is good, print the word "yes" (without the quotes), otherwise print the word "no" (without the quotes).

输入输出样例

输入样例 #1

16
.**.*..*.***.**.

输出样例 #1

yes

输入样例 #2

11
.*.*...*.*.

输出样例 #2

no

说明

In the first sample test you may perform a sequence of jumps through platforms $ 2,5,8,11,14 $ .

题意翻译

给定一段路，其中有陷阱和平台，如果踩到陷阱就算输。在平台上可以跳跃到另一个向前的平台。如果从平台 $i$ 连续跳四次，且每次跳跃长度相等，则称为这是一次好的跳跃。 现在给定一个长度为 $n$ 的字符串 $s$，其中 `.` 表示陷阱，`*` 表示平台，输出 $s$ 有无可能出现一次好的跳跃。