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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
import java.util.Scanner;

/**
 * Created with IntelliJ IDEA.
 * User: Mikle
 * Date: 04.04.15
 * Time: 23:36
 * To change this template use File | Settings | File Templates.
 */
public class ZeptoA {
    public static void main(String[] args) {
        int i, d=1, j, sum, k=0, flag=0;
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        String str = sc.nextLine();
        str = sc.nextLine();

        int a[] =new int[n];
        for (i=0;i<n;i++)
        {
            if (str.charAt(i)=='*')
            a[i]=1;
            else
                a[i]=0;

        }
        while (true)
        {sum=0;
          for (i=0;i<4;i++)
              sum+=d;
          if(n-sum<0)
              break;
          else d++;
        }
        d=d-1;
        int count =0;
      //  System.out.println(d);
        for (i=1;i<=d;i++)
        {

            for (j=0;j<n;j++)
            {
                if(a[j]==1)
                {
                    count=0;
                    sum=j;
                    for (k=0;k<4;k++)
                    {
                      sum+=i;
                        count++;
                     // System.out.println(sum+" "+count+" "+i);

                      if(sum>=n)
                          break;
                        else
                      if(a[sum]==0)
                          break;
                    }
                }

                if(k==4)
                {
                    flag=1;
                    System.out.print("yes");
                    break;
                }
            }
            if(flag==1)
                break;

        }
        if (flag==0)
            System.out.print("no");
    }
}
