20
.*..*...*....*.....*
 97
****.***.***.*..**.**.*.*.***.*............*..*......*.***.**.*.***.*.***.*..*.**.*.***.**.*****.
 5
*.***
 4
****
 11
.*.*.*.*...
 72
.***.**.*.*...*****.*.*.*.*.**....**.*.**..*.*...**..***.**.**..*.**..**
 89
..**..**..*.********....*.*****.**.****...*......*******..*.**.*****..*..****....*...**..
 6
***.**
 54
...***.*...****.*..****....*..**..**..***.*..**...**..
 100
****************************************************************************************************
 53
*.*.****.*.*......**....**.***.*.*.**.*.*.***...*..*.
 87
*..*..***.**.*...****...*....***....***......*..*.*.*****.**..*.***...*.****..**.*..***
 90
**....****.***..***.*.*****...*.*.***..***.******.**...***..*...*****..*.**.**...*..**...*
 55
...*..*.*.**..*.*....*.****..****....*..***.*****..*..*
 21
*.*...*.*...*.*...*.*
 41
*******....*..*.**..***.*...****.***.*...
 31
.******.**.**....*.*********...
 64
*.***...**...*..*...*....*..***.*.*.*.***.*.**...**.*.*.*..*....
 10
*****....*
 99
**...*.*.*..*....**.***..*...***..***.**.*.....*.*....*...*.**.**.****..**..*.*..*.***....**...**.*
 69
.***...*.***.**...*....*.***.*..*....**.*...**....*.*..**....**..*.**
 99
.*.......................*.......................*.......................*.......................*.
 98
.**..**.*****..***...*.**..*..*....*******..**....*.****.**.*.....*.**..***.**..***.*******..****.
 57
**...*....**.**.*.******.**..**.*.....**.***..***...**..*
 64
***.*...*...*.***.....*.....**.*****.*.*...*..*.*..***..*...***.
 17
*...*...*...*...*
 100
*...............................................................................................****
 11
*...**..*.*
 1
.
 100
*.....................*.....................*.....................*.....................*...........
 56
**.*..*...***.*.**.**..**.*.*.*.**...*.**.**....*...**..
 99
***....*.....****.*.**.*.*.**.*.*.*..*...*..*...***..*.*...*.*...***.*.*...**.**.*******....**....*
 10
.*.*.*.*.*
 51
....****....*........*.*..**........*....****....*.
 17
.*..*..*.....*..*
 97
...*..*...*******.*.**..**..******.*.*..*****.*...***.*.**.**.**..**.******.****.*.***.**..*...**
 42
***.*..*.*.***...**..*..**....**..*..*...*
 5
*****
 42
..*...*.*..**..*.*.*..**...**.***.*.******
 71
**.**..*****.*.*.*.********.....*****.****.*..***...*.*.*.**.****.**.**
 5
.****
 99
.*..**..*..*..**...***.****.*...*....*****.....**..****.*..*....****..**..*****..*....**.*.**..**..
 42
.*.*...*..**.****...****..*.*.***....**...
 10
.*.*.*.*..
 1
*
 5
***.*
 16
*.**.**.**.*..*.
 100
*.......................*.......................*.......................*.......................*...
 7
***.***
 58
**.*.*.**..******.**.*..*.**.*.*******.**.*.**.*..*****.*.
 67
..**.*...*.....****.***.**.*....***..***.*..***.....*******.....*.*
 99
.*.......................*...............................................*.......................*.
 6
......
 11
.**.*..*.**
 15
..........*****
 75
..*.**..*.*****.......*....*.*.*..**.*.***.*.***....******.****.*.....****.
 45
.***..******....***..**..*.*.*.**..**..*.**..
 13
*..*..*..*..*
 5
**.**
 100
*****...............................................................................................
 99
..*.*..**.*.*.******.*.*.**.**.**.*..**.*.*****..*.*.****.*....**....*****.....***..**....***.*.*.*
 99
***************************************************************************************************
 5
****.

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.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;

public class TaskBSpiderMan {
    public static void main(String[] args) throws IOException {
        TaskBSpiderMan task = new TaskBSpiderMan();
        task.resolve();
    }

    private void resolve() throws IOException {
        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
        int levelLength = Integer.parseInt(bufferedReader.readLine());
        String level = bufferedReader.readLine();

        List<Integer> maxSpaces = new ArrayList<>();
        int lastSpace = 0;

        int maxLength = levelLength / 4 + 1;
        List<Integer> squares = new ArrayList<>();
        for (int i = 0; i < level.length(); i++) {
            if (level.charAt(i) == '*') {
                squares.add(i);
                if (maxSpaces.isEmpty()) {
                    maxSpaces.add(lastSpace);
                } else {
                    maxSpaces.add(Math.max(lastSpace, maxSpaces.get(maxSpaces.size() - 1)));
                }
            }

            lastSpace++;
        }

        for (int i = 1; i < maxLength; i++) {
            for (int square : squares) {
                if (i * 4 + square >= level.length()) {
                    break;
                }

//                if (maxSpaces.get(k) > i) {
//                    break;
//                }

                for (int j = square + i; j < levelLength; j += i) {
                    if (level.charAt(j) == '.') {
                        break;
                    }

                    if (j + i >= levelLength && j >= square + i * 4) {
                        System.out.println("yes");
                        return;
                    }
                }
            }
        }

        System.out.println("no");
    }
}