20
.*..*...*....*.....*
 97
****.***.***.*..**.**.*.*.***.*............*..*......*.***.**.*.***.*.***.*..*.**.*.***.**.*****.
 5
*.***
 4
****
 11
.*.*.*.*...
 72
.***.**.*.*...*****.*.*.*.*.**....**.*.**..*.*...**..***.**.**..*.**..**
 89
..**..**..*.********....*.*****.**.****...*......*******..*.**.*****..*..****....*...**..
 6
***.**
 54
...***.*...****.*..****....*..**..**..***.*..**...**..
 100
****************************************************************************************************
 53
*.*.****.*.*......**....**.***.*.*.**.*.*.***...*..*.
 87
*..*..***.**.*...****...*....***....***......*..*.*.*****.**..*.***...*.****..**.*..***
 90
**....****.***..***.*.*****...*.*.***..***.******.**...***..*...*****..*.**.**...*..**...*
 55
...*..*.*.**..*.*....*.****..****....*..***.*****..*..*
 21
*.*...*.*...*.*...*.*
 41
*******....*..*.**..***.*...****.***.*...
 31
.******.**.**....*.*********...
 64
*.***...**...*..*...*....*..***.*.*.*.***.*.**...**.*.*.*..*....
 10
*****....*
 99
**...*.*.*..*....**.***..*...***..***.**.*.....*.*....*...*.**.**.****..**..*.*..*.***....**...**.*
 69
.***...*.***.**...*....*.***.*..*....**.*...**....*.*..**....**..*.**
 99
.*.......................*.......................*.......................*.......................*.
 98
.**..**.*****..***...*.**..*..*....*******..**....*.****.**.*.....*.**..***.**..***.*******..****.
 57
**...*....**.**.*.******.**..**.*.....**.***..***...**..*
 64
***.*...*...*.***.....*.....**.*****.*.*...*..*.*..***..*...***.
 17
*...*...*...*...*
 100
*...............................................................................................****
 11
*...**..*.*
 1
.
 100
*.....................*.....................*.....................*.....................*...........
 56
**.*..*...***.*.**.**..**.*.*.*.**...*.**.**....*...**..
 99
***....*.....****.*.**.*.*.**.*.*.*..*...*..*...***..*.*...*.*...***.*.*...**.**.*******....**....*
 10
.*.*.*.*.*
 51
....****....*........*.*..**........*....****....*.
 17
.*..*..*.....*..*
 97
...*..*...*******.*.**..**..******.*.*..*****.*...***.*.**.**.**..**.******.****.*.***.**..*...**
 42
***.*..*.*.***...**..*..**....**..*..*...*
 5
*****
 42
..*...*.*..**..*.*.*..**...**.***.*.******
 71
**.**..*****.*.*.*.********.....*****.****.*..***...*.*.*.**.****.**.**
 5
.****
 99
.*..**..*..*..**...***.****.*...*....*****.....**..****.*..*....****..**..*****..*....**.*.**..**..
 42
.*.*...*..**.****...****..*.*.***....**...
 10
.*.*.*.*..
 1
*
 5
***.*
 16
*.**.**.**.*..*.
 100
*.......................*.......................*.......................*.......................*...
 7
***.***
 58
**.*.*.**..******.**.*..*.**.*.*******.**.*.**.*..*****.*.
 67
..**.*...*.....****.***.**.*....***..***.*..***.....*******.....*.*
 99
.*.......................*...............................................*.......................*.
 6
......
 11
.**.*..*.**
 15
..........*****
 75
..*.**..*.*****.......*....*.*.*..**.*.***.*.***....******.****.*.....****.
 45
.***..******....***..**..*.*.*.**..**..*.**..
 13
*..*..*..*..*
 5
**.**
 100
*****...............................................................................................
 99
..*.*..**.*.*.******.*.*.**.**.**.*..**.*.*****..*.*.****.*....**....*****.....***..**....***.*.*.*
 99
***************************************************************************************************
 5
****.

no yes no no no yes yes no yes yes yes yes yes yes no yes yes yes yes yes yes yes yes yes yes yes no no no yes yes yes yes no no yes yes yes yes yes no yes yes no no no yes yes no yes yes no no no yes yes yes yes no yes yes yes no
# -*- coding: utf-8 -*- 
import itertools, math, random, re, string, sys
from bisect import *
from collections import *
from decimal import *
from fractions import *
from itertools import combinations, permutations, product
from math import ceil, exp, log, sqrt
from Queue import *
getcontext().prec = 100
sys.setrecursionlimit(100000)
MOD = 10 ** 9 + 7
INF = float('+inf')

n = input()
s = raw_input()

x = [i for i in xrange(n) if s[i] == '*']
if len(x) < 5:
    print 'no'
    quit()
for l in xrange(1, 101):
    for c in x:
        #print l, c, [c + l * j for j in xrange(5)]
        t = [c + l * j for j in xrange(5)]
        flag = True
        for c in t:
            if c not in x:
                flag = False
        if flag:
            print 'yes'
            quit()
print 'no'