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 static java.lang.Math.*;

public class q1 {
    
    static class Scan {

        private final InputStream inputStream;
	private final byte[] buffer = new byte[1024];
	private int currentChar;
	private int numChars;
	private SpaceCharFilter filter;

	public Scan () {
            inputStream = System.in;
	}

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

            if (currentChar >= numChars) {
		currentChar = 0;
		try {
                    numChars = inputStream.read(buffer);
		}
		catch (IOException e) {
                    throw new InputMismatchException();
		}
				
		if (numChars <= 0)				
                    return -1;
            }
            return buffer[currentChar++];
	}
	 
	public String nextLine () {
            BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
            String str = "";
            
            try {
                str = br.readLine();
            }
            catch (IOException e) {
            }
            return str;
	}
	
        public int nextInt () {	
            int ch = read();
			
            while (isSpaceChar(ch)) 
		ch = read();
			
            int sgn = 1;
			
            if (ch == '-') {
		sgn = -1;
                ch = read();
            }
			
            int res = 0;
            do {
		if (ch < '0' || ch > '9') 
                    throw new InputMismatchException();
		res *= 10;
		res += ch - '0';
		ch = read();
            }
            while (!isSpaceChar(ch)); 
			
            return res * sgn;
	}
		
	public long nextLong () {
            int ch = read();
            
            while (isSpaceChar(ch))
		ch = read();
            
            int sgn = 1;
            
            if (ch == '-') {
		sgn = -1;
		ch = read();
            }
            
            long res = 0;
			
            do {
                if (ch < '0' || ch > '9')
                    throw new InputMismatchException();
		res *= 10;
		res += ch - '0';
		ch = read();
            }
            while (!isSpaceChar(ch));
            
            return res * sgn;
	}
		
	public double nextDouble () {
            int ch = read();
		
            while (isSpaceChar(ch))
		ch = read();
            
            int sgn = 1;
            if (ch == '-') {
		sgn = -1;
		ch = read();
            }
	
            double res = 0;
            while (!isSpaceChar(ch) && ch != '.') {
		if (ch == 'e' || ch == 'E')
                    return res * Math.pow(10, nextInt());
		if (ch < '0' || ch > '9')
                    throw new InputMismatchException();
		res *= 10;
		res += ch - '0';
		ch = read();
            }
            if (ch == '.') {
		ch = read();
		double m = 1;
		while (!isSpaceChar(ch)) {
                    if (ch == 'e' || ch == 'E')
			return res * Math.pow(10, nextInt());
                    if (ch < '0' || ch > '9')
                    	throw new InputMismatchException();
                    m /= 10;
                    res += (ch - '0') * m;
                    ch = read();
		}
            }
	
            return res * sgn;
	}
		
	public String readString () {
            int ch = read();
            while (isSpaceChar(ch))
		ch = read();
	
            StringBuilder res = new StringBuilder();
	
            do {
		res.appendCodePoint(ch);
		ch = read();
            } 
            while (!isSpaceChar(ch));
			
            return res.toString();
	}
	 
	public boolean isSpaceChar (int ch) {
            if (filter != null)
		return filter.isSpaceChar(ch);
            return ch == ' ' || ch == '\n' || ch == '\r' || ch == '\t' || ch == -1;
	}
	 
	public String next () {
            return readString();
	}

        public interface SpaceCharFilter {
            public boolean isSpaceChar(int ch);
	}
    }
    
    static class Print {
        private final BufferedWriter bw;
        
        public Print () {
            this.bw=new BufferedWriter(new OutputStreamWriter(System.out));
        }
        
        public void print (Object object)throws IOException {
            bw.append(""+object);
        }
        
        public void println (Object object)throws IOException {
            print(object);
            bw.append("\n");
        }
        
        public void close () throws IOException {
            bw.close();
        }
    }
    
    public static void main (String[] args) throws IOException {
        Scan sc = new Scan();
        Print pr = new Print();
        
        String str = sc.next();
        
        String[] names = {"Danil", "Olya", "Slava", "Ann", "Nikita"};
        
        int pos[] = new int[5], i, count=0;
        
        for(i=0;i<5;i++) {
            pos[i]=str.indexOf(names[i]);
            if(pos[i]!=-1) {
                count++;
                while(pos[i]!=-1) {
                    pos[i]++;
                    pos[i]=str.indexOf(names[i], pos[i]);
                    if(pos[i]!=-1)
                        count++;
                }
            }
        }
        
        if(count==1)
            pr.println("YES");
        else
            pr.println("NO");
        
        pr.close();
    }
    
}