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****.

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
def findOccurrences(s, ch):
    return [i for i, letter in enumerate(s) if letter == ch]

if __name__ == '__main__':
    list = []
    n=int(input())
    name = input()
    list=findOccurrences(name,'*')
    result=False
    p=1
    try:
        for i in list:
            count=1
            for j in range(1,n,p):
                if i+j<n:
                    if name[i+j]==('*'):
                        count=count+1
                        if count==4:
                            result=True
                            raise Exception
                    else:
                        count=0
                if j==n-1:
                    p=p+1
                    if p==n//5:
                        break
    except Exception:
        pass
    print(result)