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
/* IMPORTANT: Multiple classes and nested static classes are supported */

/*
 * uncomment this if you want to read input.
//imports for BufferedReader
import java.io.BufferedReader;
import java.io.InputStreamReader;

//import for Scanner and other utility  classes
*/import java.util.*;


public class TestClass {
    public static void main(String args[] ) throws Exception {
        /*
         * Read input from stdin and provide input before running
         * Use either of these methods for input

        //BufferedReader
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String line = br.readLine();
        int N = Integer.parseInt(line);

        //Scanner
        Scanner s = new Scanner(System.in);
        int N = s.nextInt();

        for (int i = 0; i < N; i++) {
            System.out.println("hello world");
        }
        */
   Scanner s=new Scanner(System.in);
   HashMap<String,Integer> h=new HashMap<>();
   h.put( "Nikita",1);
   h.put( "Danil",1);
   h.put( "Olya",1);
   h.put(  "Ann",1);
   h.put(  "Slava",1);
        //System.out.println("Hello World!");\
        String str=s.next();
        boolean d=el(str,h);
        if(d)
        System.out.println("YES");
        else
        System.out.println("NO");
    }
    public static boolean el(String str,HashMap<String,Integer> h){
        boolean d=false;
        for(int i=0;i<str.length();i++){
            for(int j=i+1;j<str.length()+1;j++){
                if(h.containsKey(str.substring(i,j))){
                    if(d==true)
                    return false;
                    d=true;
                }
            }
            
        }
            return d;
        
    }
}
