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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.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class a {

    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        s.nextInt();
        String s1=s.next();
        int n=0;
        for(int i=0;i<s1.length();i++)
            if(s1.charAt(i)=='*')
                n++;
       if(n==0)
          System.out.println("no");
       else{ 
        int a[]=new int[n];
        int j=0;
        for(int i=0;i<s1.length();i++)
           if(s1.charAt(i)=='*')
              a[j++]=i+1; 
        int count1=1;
        int count2=a[n-1]-a[0];
        int flag=0;
        while(count1<=count2){
           for(int i=0;i<n;i++)
              if(f(0,n-1,a,a[i]+1*count1)&&f(0,n-1,a,a[i]+2*count1)&&f(0,n-1,a,a[i]+3*count1)&&f(0,n-1,a,a[i]+4*count1)){
                  flag=1;
                  break;
              } 
            count1++;
        }
        if(flag==0)
           System.out.println("no");
        else
           System.out.println("yes"); 
        
    }
    }
    public static boolean f(int first, int last, int array[], int search){
    int middle = (first + last)/2;
 
    while( first <= last )
    {
      if ( array[middle] < search )
        first = middle + 1;    
      else if ( array[middle] == search ) 
      {
          return true;
      }
      else
         last = middle - 1;
 
      middle = (first + last)/2;
   }
   return false;
    }
}

