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.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.InputMismatchException;

public class A_442
{

	InputStream is;
	PrintWriter out;
	int n;
	long a[];
	private boolean oj = System.getProperty("ONLINE_JUDGE") != null;

	void solve()
	{
		String s = ns();
		int t1 = S(s, "Danil");
		int t2 = S(s, "Olya");
		int t3 = S(s, "Slava");
		int t4 = S(s, "Ann");
		int t5 = S(s, "Nikita");
		tr(t1, t2, t3, t4, t5);
		if (t1 == 1 && t2 == 0 && t3 == 0 && t4 == 0 && t5 == 0)
		{
			out.println("YES");
		} else if (t1 == 0 && t2 == 1 && t3 == 0 && t4 == 0 && t5 == 0)
		{
			out.println("YES");
		} else if (t1 == 0 && t2 == 0 && t3 == 1 && t4 == 0 && t5 == 0)
		{
			out.println("YES");
		} else if (t1 == 0 && t2 == 0 && t3 == 0 && t4 == 1 && t5 == 0)
		{
			out.println("YES");
		} else if (t1 == 0 && t2 == 0 && t3 == 0 && t4 == 0 && t5 == 1)
		{
			out.println("YES");
		} else
			out.println("NO");
	}

	int S(String s, String c)
	{
		int count = 0;
		for (int i = 0; i < s.length(); i++)
		{
			if (s.charAt(i) == c.charAt(0) && s.length() - i >= c.length())
			{
				boolean flag = true;
				tr(c);
				for (int j = i; (j - i) < c.length() && j < s.length(); j++)
				{
					tr(s.charAt(j), c.charAt(j - i), c);
					if (s.charAt(j) != c.charAt(j - i))
					{

						flag = false;
					}
				}
				if (flag)
				{
					count++;
				}
			}
		}
		return count;
	}

	void run() throws Exception
	{
		String INPUT = "C:\\Users\\Admin\\Desktop\\input.txt";
		is = oj ? System.in : new FileInputStream(INPUT);
		out = new PrintWriter(System.out);

		long s = System.currentTimeMillis();
		solve();
		out.flush();
		tr(System.currentTimeMillis() - s + "ms");
	}

	public static void main(String[] args) throws Exception
	{
		new Thread(null, new Runnable()
		{
			public void run()
			{
				try
				{
					new A_442().run();
				} catch (Exception e)
				{
					e.printStackTrace();
				}
			}
		}, "1", 1 << 26).start();
	}

	private byte[] inbuf = new byte[1024];
	public int lenbuf = 0, ptrbuf = 0;

	private int readByte()
	{
		if (lenbuf == -1)
			throw new InputMismatchException();
		if (ptrbuf >= lenbuf)
		{
			ptrbuf = 0;
			try
			{
				lenbuf = is.read(inbuf);
			} catch (IOException e)
			{
				throw new InputMismatchException();
			}
			if (lenbuf <= 0)
				return -1;
		}
		return inbuf[ptrbuf++];
	}

	private boolean isSpaceChar(int c)
	{
		return !(c >= 33 && c <= 126);
	}

	private int skip()
	{
		int b;
		while ((b = readByte()) != -1 && isSpaceChar(b))
			;
		return b;
	}

	private double nd()
	{
		return Double.parseDouble(ns());
	}

	private char nc()
	{
		return (char) skip();
	}

	private String ns()
	{
		int b = skip();
		StringBuilder sb = new StringBuilder();
		while (!(isSpaceChar(b)))
		{ // when nextLine, (isSpaceChar(b) && b != ' ')
			sb.appendCodePoint(b);
			b = readByte();
		}
		return sb.toString();
	}

	private char[] ns(int n)
	{
		char[] buf = new char[n];
		int b = skip(), p = 0;
		while (p < n && !(isSpaceChar(b)))
		{
			buf[p++] = (char) b;
			b = readByte();
		}
		return n == p ? buf : Arrays.copyOf(buf, p);
	}

	private char[][] nm(int n, int m)
	{
		char[][] map = new char[n][];
		for (int i = 0; i < n; i++)
			map[i] = ns(m);
		return map;
	}

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

	private int ni()
	{
		int num = 0, b;
		boolean minus = false;
		while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'))
			;
		if (b == '-')
		{
			minus = true;
			b = readByte();
		}

		while (true)
		{
			if (b >= '0' && b <= '9')
			{
				num = num * 10 + (b - '0');
			} else
			{
				return minus ? -num : num;
			}
			b = readByte();
		}
	}

	private long nl()
	{
		long num = 0;
		int b;
		boolean minus = false;
		while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'))
			;
		if (b == '-')
		{
			minus = true;
			b = readByte();
		}

		while (true)
		{
			if (b >= '0' && b <= '9')
			{
				num = num * 10 + (b - '0');
			} else
			{
				return minus ? -num : num;
			}
			b = readByte();
		}
	}

	private void tr(Object... o)
	{
		if (!oj)
			System.out.println(Arrays.deepToString(o));
	}

}
