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 Main {

    static int M = 1_000_000_007;
    static int INF = 2_000_000_000;
    static int N = (int)1e5+1;
    static final FastScanner fs = new FastScanner();

    //variable

    public static void main(String[] args) throws IOException {

        StringBuilder s = new StringBuilder(fs.next());
            String[] names = { "Danil", "Olya", "Slava", "Ann", "Nikita"};
            int cnt = 0;
            for(int i=0;i< names.length;i++) {
                int j = s.indexOf(names[i]);
                int k = s.lastIndexOf(names[i]);

                if(j!=-1) {
                    cnt++;
                    if(j != k) cnt++;
                }
            }
        System.out.println(cnt == 1? "YES":"NO");
    }
    //class

    //function

    // Template

    static long lcm(long a, long b) {
        return (a / gcd(a, b)) * b;
    }

    static long gcd(long a, long b) {
        if(a==0) return b;

        return gcd(b%a,a);
    }
    static void premutation(int n, ArrayList<Integer> arr,boolean[] chosen) {
        if(arr.size() == n) {
            System.out.println(arr);
        }else {
            for(int i=1; i<=n; i++) {
                if(chosen[i]) continue;
                arr.add(i);
                chosen[i] = true;
                premutation(n,arr,chosen);
                arr.remove(new Integer(i));
                chosen[i] = false;
            }
        }
    }
    static boolean isPalindrome(char[] c) {
        int n = c.length;
        for(int i=0; i<n/2; i++) {
            if(c[i] != c[n-i-1]) return false;
        }
        return true;
    }

    static long nCk(int n, int k) {
        return (modMult(fact(n),fastexp(modMult(fact(n-k),fact(k)),M-2)));
    }

    static long fact (long n) {

        long fact =1;
        for(int i=1; i<=n; i++) {
            fact = modMult(fact,i);
        }
        return fact%M;
    }

    static int modMult(long a,long b) {
        return (int) (a*b%M);
    }
    static int negMult(long a,long b) {
        return (int)((a*b)%M + M)%M;
    }
    static long fastexp(long x, int y){
        if(y==1) return x;

        long ans = fastexp(x,y/2);
        if(y%2 == 0) return modMult(ans,ans);
        else return modMult(ans,modMult(ans,x));
    }

    static final Random random = new Random();

    static void ruffleSort(int[] arr)
    {
        int n = arr.length;
        for(int i=0; i<n; i++)
        {
            int j = random.nextInt(n);
            int temp = arr[j];
            arr[j] = arr[i];
            arr[i] = temp;
        }
        Arrays.sort(arr);
    }


    public static class Pairs implements Comparable<Pairs>
    {
        int f,s;
        Pairs(int f, int s)
        {
            this.f = f;
            this.s = s;
        }
        public int compareTo(Pairs p)
        {
            return Integer.compare(this.f,p.f);
        }

        @Override
        public boolean equals(Object o) {
            if (this == o) return true;
            if (!(o instanceof Pairs)) return false;
            Pairs pairs = (Pairs) o;
            return f == pairs.f && s == pairs.s;
        }

        @Override
        public int hashCode() {
            return Objects.hash(f, s);
        }
    }
}
class FastScanner
{
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer str = new StringTokenizer("");

    String next() throws IOException
    {
        while(!str.hasMoreTokens())
            str = new StringTokenizer(br.readLine());

        return str.nextToken();
    }

    char nextChar() throws IOException {
        return next().charAt(0);
    }

    int nextInt() throws IOException
    {
        return Integer.parseInt(next());
    }

    float nextFloat() throws IOException
    {
        return Float.parseFloat(next());
    }

    double nextDouble() throws IOException
    {
        return Double.parseDouble(next());
    }
    long nextLong() throws IOException
    {
        return Long.parseLong(next());
    }
    byte nextByte() throws IOException
    {
        return Byte.parseByte(next());
    }
    int [] arrayIn(int n) throws IOException
    {
        int[] arr = new int[n];
        for(int i=0; i<n; i++)
        {
            arr[i] = nextInt();
        }
        return arr;
    }
}