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.util.*;
import java.io.*;
import java.lang.*;
import java.math.*;
import java.util.concurrent.ThreadLocalRandom;

import static java.lang.Math.*;

public class Sol {

    static long mod = 1000000007;

    // *********** Code starts here ***************

    static void solve(int total_test_cases, InputReader in, PrintWriter w) {
        for (int test_case = 1; test_case <= total_test_cases; test_case++) {
            String s = in.next();
            HashSet<String> set = new HashSet<>();
            set.add("Danil");
            set.add("Olya");
            set.add("Slava");
            set.add("Ann");
            set.add("Nikita");

            int count = 0;

            for(int i=0;i<s.length();i++) {
                for(int j=i+1;j<=s.length();j++) {
                    String str = s.substring(i, j);

                    if(set.contains(str)) count++;
                }
            }

            if(count == 1) w.println("YES");
            else w.println("NO");
        }
    }

    // ************* Code ends here ***************

    public static void main(String args[]) throws Exception {
        //Scanner in;
        InputReader in;
        PrintWriter w;
        boolean online = false;
        String common_in_fileName = "C:\\Users\\lenovo123\\Desktop\\Psp98\\Events\\HackerEarth\\Recruit\\Easy\\Powers of primes\\files\\Samplein";
        String common_out_fileName = "C:\\Users\\lenovo123\\Desktop\\Psp98\\Events\\HackerEarth\\Recruit\\Easy\\Powers of primes\\files\\in";
        int test_files = 11;

        for(int file_no = 11; file_no <= test_files; file_no++) {

            String x = "" + file_no;
            if(x.length() == 1) x = "0" + x;

            String in_fileName = common_in_fileName;// + "" + x;
            String out_fileName = common_out_fileName + "" + x;

            if (online) {
                //in = new Scanner(new File(in_fileName + ".txt"));
                in = new InputReader(new FileInputStream(new File(in_fileName + ".txt")));
                w = new PrintWriter(new FileWriter(out_fileName + ".txt"));
            } else {
                //in = new Scanner(System.in);
                in = new InputReader(System.in);
                w = new PrintWriter(System.out);
            }

            solve(1, in, w);
            w.close();
        }
    }

    static class InputReader {

        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private SpaceCharFilter filter;

        public InputReader(InputStream stream) {
            this.stream = stream;
        }

        public int read() {
            if (numChars == -1) {
                throw new InputMismatchException();
            }

            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }

                if (numChars <= 0) {
                    return -1;
                }
            }
            return buf[curChar++];
        }

        public String nextLine() {
            BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
            String str = "";
            try {
                str = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }

        public int nextInt() {
            int c = read();

            while (isSpaceChar(c)) {
                c = read();
            }

            int sgn = 1;

            if (c == '-') {
                sgn = -1;
                c = read();
            }

            int res = 0;
            do {
                if (c < '0' || c > '9') {
                    throw new InputMismatchException();
                }
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));

            return res * sgn;
        }

        public long nextLong() {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            long res = 0;

            do {
                if (c < '0' || c > '9') {
                    throw new InputMismatchException();
                }
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }

        public double nextDouble() {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            double res = 0;
            while (!isSpaceChar(c) && c != '.') {
                if (c == 'e' || c == 'E') {
                    return res * Math.pow(10, nextInt());
                }
                if (c < '0' || c > '9') {
                    throw new InputMismatchException();
                }
                res *= 10;
                res += c - '0';
                c = read();
            }
            if (c == '.') {
                c = read();
                double m = 1;
                while (!isSpaceChar(c)) {
                    if (c == 'e' || c == 'E') {
                        return res * Math.pow(10, nextInt());
                    }
                    if (c < '0' || c > '9') {
                        throw new InputMismatchException();
                    }
                    m /= 10;
                    res += (c - '0') * m;
                    c = read();
                }
            }
            return res * sgn;
        }

        public String readString() {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            StringBuilder res = new StringBuilder();
            do {
                res.appendCodePoint(c);
                c = read();
            } while (!isSpaceChar(c));

            return res.toString();
        }

        public boolean isSpaceChar(int c) {
            if (filter != null) {
                return filter.isSpaceChar(c);
            }
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        public String next() {
            return readString();
        }

        public interface SpaceCharFilter {

            public boolean isSpaceChar(int ch);
        }
    }
}


