One day Alex was creating a contest about his friends, but accidentally deleted it. Fortunately, all the problems were saved, but now he needs to find them among other problems.

But there are too many problems, to do it manually. Alex asks you to write a program, which will determine if a problem is from this contest by its name.

It is known, that problem is from this contest if and only if its name contains one of Alex's friends' name exactly once. His friends' names are "Danil", "Olya", "Slava", "Ann" and "Nikita".

Names are case sensitive.

Input

The only line contains string from lowercase and uppercase letters and "_" symbols of length, not more than 100 — the name of the problem.

Output

Print "YES", if problem is from this contest, and "NO" otherwise.

Examples

Input

Alex_and_broken_contest


Output

NO

Input

NikitaAndString


Output

YES

Input

Danil_and_Olya


Output

NO
import java.io.*;
import java.util.StringTokenizer;

public class AlexAndBrokenContest {

    public static void main(String[] args) throws IOException {
        MyScanner sc = new MyScanner(System.in);
        PrintWriter out = new PrintWriter(System.out);
        String s = sc.nextLine();
        int cnt = 0;
        for (int i = 0; i < s.length(); i++) {
            if (i + 4 < s.length()) {
                if (s.substring(i, i + 5).equals("Danil"))
                    cnt++;
                if (s.substring(i, i + 5).equals("Slava"))
                    cnt++;
            }
            if (i + 3 < s.length())
                if (s.substring(i, i + 4).equals("Olya"))
                    cnt++;
            if (i + 2 < s.length())
                if (s.substring(i, i + 3).equals("Ann"))
                    cnt++;
            if (i + 5 < s.length())
                if (s.substring(i, i + 6).equals("Nikita"))
                    cnt++;
        }
        out.println(cnt == 1 ? "YES" : "NO");
        out.flush();
        out.close();
    }

    static class MyScanner {
        StringTokenizer st;
        BufferedReader br;

        public MyScanner(InputStream s) {
            br = new BufferedReader(new InputStreamReader(s));
        }

        public MyScanner(String filename) throws IOException {
            br = new BufferedReader(new FileReader(new File(filename)));
        }

        public String next() throws IOException {
            while (st == null || !st.hasMoreTokens())
                st = new StringTokenizer(br.readLine());
            return st.nextToken();
        }

        public int nextInt() throws IOException {
            return Integer.parseInt(next());
        }

        public long nextLong() throws IOException {
            return Long.parseLong(next());
        }

        public String nextLine() throws IOException {
            return br.readLine();
        }

        public double nextDouble() throws IOException {
            String x = next();
            StringBuilder sb = new StringBuilder("0");
            double res = 0, f = 1;
            boolean dec = false, neg = false;
            int start = 0;
            if (x.charAt(0) == '-') {
                neg = true;
                start++;
            }
            for (int i = start; i < x.length(); i++)
                if (x.charAt(i) == '.') {
                    res = Long.parseLong(sb.toString());
                    sb = new StringBuilder("0");
                    dec = true;
                } else {
                    sb.append(x.charAt(i));
                    if (dec)
                        f *= 10;
                }
            res += Long.parseLong(sb.toString()) / f;
            return res * (neg ? -1 : 1);
        }

        public boolean ready() throws IOException {
            return br.ready();
        }
    }
}
