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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.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Scanner;

/**
 *
 * @author Thu Hoa
 */
public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        String st = sc.next();
        List<Integer> nums = new ArrayList<Integer>();
        for (int i = 0; i < st.length(); i++) {
            if (st.charAt(i) == '*') {
                nums.add(i + 1);
            }
        }
        if (nums.size() < 5) {
            System.out.println("no");
        } else {
            Map map = new HashMap();
            for (int i = nums.size() - 1; i > 0; i--) {
                int key = i;
                List<Integer> value = new ArrayList<Integer>();
                map.put(key, value);
            }

            for (int i = nums.size() - 1; i > 0; i--) {
                Integer key = i;
                List<Integer> value = (List<Integer>) map.get(key);
                for (int j = i - 1; j >= 0; j--) {
                    value.add(nums.get(i) - nums.get(j));
                }
            }
            List<Integer> lst = (List<Integer>) map.get(nums.size() - 1);
            map.remove(nums.size() - 1);
            int check = 0;
            for (int i = 0; i < lst.size(); i++) {
                int compareNum = lst.get(i);
                int mainCount = 0;
                for (Object value : map.values()) {
                    List<Integer> temp = (List<Integer>) value;
                    int count = 0;
                    for (int j = 0; j < temp.size(); j++) {
                        if (compareNum == temp.get(j)) {
                            count++;
                        }
                    }
                    if (count != 0) {
                        mainCount++;
                    }
                    if (mainCount == 3) {
                        check++;
                        break;
                    }
                }

            }
            if (check != 0) {
                System.out.println("yes");
            } else {
                System.out.println("no");

            }
        }
    }
}