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.*;

public class CODEFORCES
{
	@SuppressWarnings("rawtypes")
	static InputReader in;
	static PrintWriter out;

	static String a[];

	static int ret(String c, int ind)
	{
		for (int i = 0; i < 5; i++)
		{
			if (ind + a[i].length() <= c.length())
				if (c.substring(ind, ind + a[i].length()).compareTo(a[i]) == 0)
					return i;
		}
		return 5;
	}

	static void solve()
	{
		a = new String[5];
		a[0] = "Danil";
		a[1] = "Olya";
		a[2] = "Slava";
		a[3] = "Ann";
		a[4] = "Nikita";
		int fre[] = new int[6];
		String b = in.nextLine();
		boolean u = false;
		for (int i = 0; i < b.length(); i++)
			fre[ret(b, i)]++;
		boolean v = true;
		for (int i = 0; i < 5; i++)
		{
			if (fre[i] > 1)
			{
				v = false;
				break;
			} else if (fre[i] == 1 && u)
			{
				v = false;
				break;
			} else if (fre[i] == 1 & !u)
				u = true;
		}
		if (u & v)
			out.println("YES");
		else
			out.println("NO");
	}

	@SuppressWarnings("rawtypes")
	static void soln()
	{
		in = new InputReader(System.in);
		out = new PrintWriter(System.out);
		solve();
		out.flush();
	}

	static void debug(Object... o)
	{
		System.out.println(Arrays.deepToString(o));
	}

	public static void main(String[] args)
	{
		new Thread(null, new Runnable()
		{
			public void run()
			{
				try
				{
					soln();
				} catch (Exception e)
				{
					e.printStackTrace();
				}
			}
		}, "1", 1 << 26).start();
	}

	// To Get Input
	// Some Buffer Methods
	static class InputReader<SpaceCharFilter>
	{

		private final InputStream stream;
		private final byte[] buf = new byte[8192];
		private int curChar, snumChars;
		private SpaceCharFilter filter;

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

		public int snext()
		{
			if (snumChars == -1)
				throw new InputMismatchException();
			if (curChar >= snumChars)
			{
				curChar = 0;
				try
				{
					snumChars = stream.read(buf);
				} catch (IOException e)
				{
					throw new InputMismatchException();
				}
				if (snumChars <= 0)
					return -1;
			}
			return buf[curChar++];
		}

		public int ni()
		{
			int c = snext();
			while (isSpaceChar(c))
			{
				c = snext();
			}
			int sgn = 1;
			if (c == '-')
			{
				sgn = -1;
				c = snext();
			}
			int res = 0;
			do
			{
				if (c < '0' || c > '9')
					throw new InputMismatchException();
				res *= 10;
				res += c - '0';
				c = snext();
			} while (!isSpaceChar(c));
			return res * sgn;
		}

		public long nl()
		{
			int c = snext();
			while (isSpaceChar(c))
			{
				c = snext();
			}
			int sgn = 1;
			if (c == '-')
			{
				sgn = -1;
				c = snext();
			}
			long res = 0;
			do
			{
				if (c < '0' || c > '9')
					throw new InputMismatchException();
				res *= 10;
				res += c - '0';
				c = snext();
			} while (!isSpaceChar(c));
			return res * sgn;
		}

		public int[] nextIntArray(int n)
		{
			int a[] = new int[n];
			for (int i = 0; i < n; i++)
			{
				a[i] = ni();
			}
			return a;
		}

		public long[] nextLongArray(int n)
		{
			long a[] = new long[n];
			for (int i = 0; i < n; i++)
			{
				a[i] = nl();
			}
			return a;
		}

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

		public String nextLine()
		{
			int c = snext();
			while (isSpaceChar(c))
				c = snext();
			StringBuilder res = new StringBuilder();
			do
			{
				res.appendCodePoint(c);
				c = snext();
			} while (!isEndOfLine(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;
		}

		private boolean isEndOfLine(int c)
		{
			return c == '\n' || c == '\r' || c == -1;
		}

		public interface SpaceCharFilter
		{
			public boolean isSpaceChar(int ch);
		}

	}
}