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.text.*;
import java.math.*;
import static java.lang.Integer.*;
import static java.lang.Double.*;
import java.lang.Math.*;

public class alex_and_broken_contest {

	public static FastIO file = new FastIO();

	public static int ntc, ctc;
	public static final long MOD = 1000000007L; //998244353L;
	public static final int N = 200005, dx[] = { 0, 1, 0, -1 }, dy[] = { 1, 0, -1, 0 };

	public void run() throws Exception {
		ntc = 1; //nextInt();
		for (ctc = 1; ctc <= ntc; ++ctc)
			solve();
		file.out.flush();
		file.out.close();
	}

	public static void solve() {
		String s = next();
		int cnt = 0;
		for (int i = 0; i < s.length(); i++) {
			String x = s.substring(i);
			if (x.startsWith("Danil")) cnt++;
			if (x.startsWith("Olya")) cnt++;
			if (x.startsWith("Slava")) cnt++;
			if (x.startsWith("Ann")) cnt++;
			if (x.startsWith("Nikita")) cnt++;
		}
		println(cnt == 1 ? "YES" : "NO");
	}

	public static long mod(long n, long mod) {
		return (n % mod + mod) % mod;
	}

	public static long pow(long n, long p, long mod) {
		long ret = 1L;
		while (p > 0) {
			if (p % 2 != 0L)
				ret = mod(ret * n, mod);
			n = mod(n * n, mod);
			p >>= 1L;
		}
		return ret;
	}

	public static long pow(long n, long p) {
		long ret = 1L;
		while (p > 0) {
			if (p % 2 != 0L)
				ret *= n;
			n *= n;
			p >>= 1L;
		}
		return ret;
	}

	public static long gcd(long x, long y) {
		while (x != 0) {
			long tmp = x;
			x = y % x;
			y = tmp;
		}
		return y;
	}

	public static long lcm(long x, long y) {
		return x / gcd(x, y) * y;
	}

	public static boolean isPrime(int n) {
		if (n <= 1)
			return false;
		if (n <= 3)
			return true;
		if (n % 2 == 0 || n % 3 == 0)
			return false;
		for (int i = 5; i * i <= n; i = i + 6)
			if (n % i == 0 || n % (i + 2) == 0)
				return false;
		return true;
	}

	public static class Pair<A, B> implements Comparable {
		public A fi;
		public B se;

		public Pair(A fi, B se) {
			this.fi = fi;
			this.se = se;
		}

		@Override
		public boolean equals(Object o) {
			if (this == o)
				return true;
			if (o == null || getClass() != o.getClass())
				return false;
			Pair<?, ?> p = (Pair<?, ?>) o;
			if (!fi.equals(p.fi))
				return false;
			return se.equals(p.se);
		}

		@Override
		public int hashCode() {
			return 31 * fi.hashCode() + se.hashCode();
		}

		@Override
		public String toString() {
			return fi.toString() + " " + se.toString();
		}

		public static <A, B> Pair<A, B> of(A a, B b) {
			return new Pair<A, B>(a, b);
		}

		public int compareTo(Object o) {
			Pair<?, ?> p = (Pair<?, ?>) o;
			if (fi.equals(p.fi))
				return ((Comparable) se).compareTo(p.se);
			return ((Comparable) fi).compareTo(p.fi);
		}
	}

	public static String next() {
		return file.next();
	}

	public static int nextInt() {
		return file.nextInt();
	}

	public static long nextLong() {
		return file.nextLong();
	}

	public static double nextDouble() {
		return file.nextDouble();
	}

	public static String nextLine() {
		return file.nextLine();
	}

	public static void print(Object o) {
		file.out.print(o);
	}

	public static void println(Object o) {
		file.out.println(o);
	}

	public static void printf(String s, Object... o) {
		file.out.printf(s, o);
	}

	public static class FastIO {
		BufferedReader br;
		StringTokenizer st;
		PrintWriter out;

		public FastIO() {
			br = new BufferedReader(new InputStreamReader(System.in));
			out = new PrintWriter(System.out);
		}

		String next() {
			while (st == null || !st.hasMoreElements()) {
				try {
					st = new StringTokenizer(br.readLine());
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			return st.nextToken();
		}

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

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

		double nextDouble() {
			return Double.parseDouble(next());
		}

		String nextLine() {
			String str = "";
			try {
				str = br.readLine();
			} catch (IOException e) {
				e.printStackTrace();
			}
			return str;
		}

		void print(Object o) {
			out.print(o);
		}

		void println(Object o) {
			out.println(o);
		}

		void printf(String s, Object... o) {
			out.printf(s, o);
		}
	}

	public static void main(String[] args) throws Exception {
		new alex_and_broken_contest().run();
	}
}
