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.* ;
import java.util.stream.* ;
import java.text.* ;
import java.math.* ;
public class Codeshefcode{
	public static void main(String[] args) throws IOException{
		Solver Machine = new Solver() ;
		Machine.Solve() ;	
		Machine.Finish();
	}	
}
class Mod{
	static long mod=1000000007 ;
	static long d(long a,long b){ return (a*MI(b))%mod ; }
	static long m(long a , long b){ return (a*b)%mod ; }
	static private long MI(long a ){ return pow(a,mod-2) ; }
	static long pow(long a,long b){
		if(b<0) return pow(MI(a),-b) ;
		long val=a ; long ans=1 ;
		while(b!=0){
			if((b&1)==1) ans = (ans*val)%mod ; 
			val = (val*val)%mod ; 
			b>>=1 ;
		}
		return ans ;
	}	
}
class pair implements Comparable<pair>{
	long x ; long y ; 
	pair(long x,long y){ this.x=x ; this.y=y ;}
	public int compareTo(pair p){
		return (this.x<p.x ? -1 : (this.x>p.x ? 1 : (this.y<p.y ? -1 : (this.y>p.y ? 1 : 0)))) ;
	}
}
class Solver{	
	FasterScanner ip = new FasterScanner(System.in) ;	  
	PrintWriter op = new PrintWriter(System.out) ;
	void Solve() throws IOException{
		String s = ip.S() ;
		String arr[] = {"Danil","Olya","Slava","Ann","Nikita"} ;
		int ct=0 ;
		for(String elem : arr)
			for(int i=s.indexOf(elem) ; i!=-1 ; i=s.indexOf(elem,i+1)) ct++ ;
		pln(ct==1 ? "YES" : "NO") ;
	}
	void p(Object o){
		op.print(o) ;
	}
	void pln(Object o){
		op.println(o) ;
	}
	void pArr(String name,Object arr,char type){
		p(name+": [") ;
		if(type=='i'){ 
			int arr1[] = (int[]) arr ;
			for(int i=0 ; i<arr1.length ; i++) p(arr1[i]+(i+1==arr1.length ? "" : ",")) ;		 
		}else if(type=='l'){ 
			long arr1[] = (long[]) arr ;
			for(int i=0 ; i<arr1.length ; i++) p(arr1[i]+(i+1==arr1.length ? "" : ",")) ;
		}else if(type=='b'){
			boolean arr1[] = (boolean[]) arr ;
			for(int i=0 ; i<arr1.length ; i++) p((arr1[i] ? 1 : 0)+(i+1==arr1.length ? "" : ",")) ;
		}
		pln("]") ;
	}	
	void Finish(){
		op.flush();
		op.close();
	}	
}
@SuppressWarnings("serial")
class mylist extends ArrayList<Integer>{
}
@SuppressWarnings("serial")
class myset extends TreeSet<Long>{
 
}
@SuppressWarnings("serial")
class mystack extends Stack<Integer>{
}
@SuppressWarnings("serial")
class mymap extends TreeMap<Long,Integer>{
}
class FasterScanner { 
	private InputStream mIs;
	private byte[] buf = new byte[1024];
	private int curChar,numChars;
	public FasterScanner() { this(System.in); } 
	public FasterScanner(InputStream is) { mIs = is;} 
	public int read() {
		if (numChars == -1) throw new InputMismatchException();    
		if (curChar >= numChars) {
			curChar = 0;
			try { numChars = mIs.read(buf);} catch (IOException e) { throw new InputMismatchException();}
			if (numChars <= 0) return -1;            
		}
		return buf[curChar++];
	} 
	public String nextLine(){
		int c = read();
		while (isSpaceChar(c)) c = read();        
		StringBuilder res = new StringBuilder();
		do {
			res.appendCodePoint(c);
			c = read();
		} while (!isEndOfLine(c));
		return res.toString();
	} 
	public String S(){
		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 long l(){
		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 int i(){
		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 int[] ia(int n){
		int a[] = new int[n] ;
		for(int i=0 ; i<n ; i++) a[i] = i() ;
		return a ;
	}
	public long[] la(int n){
		long a[] = new long[n] ;
		for(int i=0 ; i<n ; i++) a[i] = l() ;
		return a ;
	}
	public boolean isSpaceChar(int c) { return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1; } 
	public boolean isEndOfLine(int c) { return c == '\n' || c == '\r' || c == -1; } 
}