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 static java.util.stream.Collectors.toList;

public class Solution {


    static MyScanner sc;
    private static PrintWriter out;
    static long M = 1000000007;

    public static void main(String[] s) throws Exception {
        StringBuilder stringBuilder = new StringBuilder();


        if (stringBuilder.length() == 0) {
            sc = new MyScanner(System.in);
        } else {
            sc = new MyScanner(new BufferedReader(new StringReader(stringBuilder.toString())));
        }

        out = new PrintWriter(new OutputStreamWriter(System.out));

        initData();
        solve();
        out.flush();
    }

    private static void initData() {

    }


    private static void solve() throws IOException {
        String[] ppp = new String[]{"Danil", "Olya", "Slava", "Ann", "Nikita"};


        String p = sc.next();
        int l = 0;
        for (String t : ppp) {
            if (p.lastIndexOf(t) == -1) continue;
            if (p.indexOf(t) == p.lastIndexOf(t)) {
                l++;
            } else {
                l+=2;
            }
        }
        if (l == 1) {
            out.println("YES");
        } else {
            out.println("NO");
        }


    }


    private static void solveT() throws IOException {
        int t = sc.nextInt();
        while (t-- > 0) {
            solve();
        }
    }


    private static long gcd(long l, long l1) {
        if (l > l1) return gcd(l1, l);
        if (l == 0) return l1;
        return gcd(l1 % l, l);
    }

    private static long pow(long a, long b, long m) {
        if (b == 0) return 1;
        if (b == 1) return a;
        long pp = pow(a, b / 2, m);
        pp *= pp;
        pp %= m;
        return (pp * (b % 2 == 0 ? 1 : a)) % m;
    }


    static class MyScanner {
        BufferedReader br;
        StringTokenizer st;

        MyScanner(BufferedReader br) {
            this.br = br;
        }

        public MyScanner(InputStream in) {
            this(new BufferedReader(new InputStreamReader(in)));
        }

        void findToken() {
            while (st == null || !st.hasMoreTokens()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
        }

        String next() {
            findToken();
            return st.nextToken();
        }

        Integer[] nab(int n) {
            Integer[] k = new Integer[n];
            for (int i = 0; i < n; i++) {
                k[i] = sc.fi();
            }
            return k;
        }

        int[] na(int n) {
            int[] k = new int[n];
            for (int i = 0; i < n; i++) {
                k[i] = sc.fi();
            }
            return k;
        }

        long[] nl(int n) {
            long[] k = new long[n];
            for (int i = 0; i < n; i++) {
                k[i] = sc.nextLong();
            }
            return k;
        }

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

        int fi() {
            String t = next();
            int cur = 0;
            boolean n = t.charAt(0) == '-';
            for (int a = n ? 1 : 0; a < t.length(); a++) {
                cur = cur * 10 + t.charAt(a) - '0';
            }
            return n ? -cur : cur;
        }

        long nextLong() {
            return Long.parseLong(next());
        }

        double nextDouble() {
            return Double.parseDouble(next());
        }
    }

    private static final class STree {
        private final boolean maxt;
        int rs;
        int[] val1;
        int[] from1;
        int[] to1;
        int[] metric;

        public STree(int c, boolean maxt) {
            rs = c;
            this.maxt = maxt;
            int size = Integer.highestOneBit(c);
            if (size != c) {
                size <<= 1;
            }
            int rs = size << 1;
            val1 = new int[rs];
            from1 = new int[rs];
            metric = new int[rs];
            to1 = new int[rs];

            Arrays.fill(from1, Integer.MAX_VALUE);
            if (!maxt)
                Arrays.fill(metric, Integer.MAX_VALUE);
            for (int r = rs - 1; r > 1; r--) {
                if (r >= size) {
                    from1[r] = r - size;
                    to1[r] = r - size;
                }
                from1[r / 2] = Math.min(from1[r / 2], from1[r]);
                to1[r / 2] = Math.max(to1[r / 2], to1[r]);
            }
        }

        public STree(int c) {
            this(c, true);
        }

        public int max(int from, int to) {
            return max(1, from, to);
        }

        private int max(int cur, int from, int to) {
            if (cur >= val1.length) return 0;
            if (from <= from1[cur] && to1[cur] <= to) {
                return metric[cur];
            }
            if (from1[cur] > to || from > to1[cur]) {
                return 0;
            }
            cur <<= 1;
            return Math.max(max(cur, from, to), max(cur + 1, from, to));
        }


        public void put(int x, int val) {
            x += val1.length >> 1;
            val1[x] = val;
            metric[x] = val;
            addToParent(x);
        }


        private void addToParent(int cur) {
            while (cur > 1) {
                cur >>= 1;
                if (maxt) {
                    metric[cur] = Math.max(metric[cur << 1], metric[1 + (cur << 1)]);
                } else {
                    metric[cur] = Math.min(metric[cur << 1], metric[1 + (cur << 1)]);
                }

            }
        }

        public long x(int i) {
            return val1[i + val1.length >> 1];
        }
    }
}