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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.*;

public class SumaDeString {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = Integer.parseInt(in.nextLine().trim());
        String a = in.nextLine();
        ArrayList<Integer> ww = new ArrayList();
        for (int i = 0; i < n; i++) {
            if (a.charAt(i) != '.') {
                ww.add(i + 1);
            }
        }
        int c = 0;
        int j = c + 1;
        int u = j;
        int weed = 1;
        int x = 3;
        boolean d = false;
        String men = "no";
        while (c < (ww.size() - 3) && d == false && ww.size() > 3) {
            int A = ww.get(c);//2
            while (j < ww.size() - x && d == false) {
                int B = ww.get(j);//5
                int N = B - A;//3
                int aux = j;
                do {
                    d = false;
                    for (int i = aux; i < ww.size(); i++) {
                        if (B + N == ww.get(i)) {
                            weed++;
                            d = true;
                            B += N;
                            aux = i;
                            break;
                        }
                    }
                    if (weed == 4) {
                        men = "yes";
                        break;
                    }
                } while (d);
                j++;
                weed = 1;
            }
            u++;
            j = u;
            x++;
            c++;
        }
        System.out.println(men);
    }
}
