One day in the IT lesson Anna and Maria learned about the lexicographic order.

String x is lexicographically less than string y, if either x is a prefix of y (and x ≠ y), or there exists such i (1 ≤ i ≤ min(|x|, |y|)), that xi < yi, and for any j (1 ≤ j < i) xj = yj. Here |a| denotes the length of the string a. The lexicographic comparison of strings is implemented by operator < in modern programming languages​​.

The teacher gave Anna and Maria homework. She gave them a string of length n. They should write out all substrings of the given string, including the whole initial string, and the equal substrings (for example, one should write out the following substrings from the string "aab": "a", "a", "aa", "ab", "aab", "b"). The resulting strings should be sorted in the lexicographical order. The cunning teacher doesn't want to check all these strings. That's why she said to find only the k-th string from the list. Help Anna and Maria do the homework.

Input

The first line contains a non-empty string that only consists of small Latin letters ("a"-"z"), whose length does not exceed 105. The second line contains the only integer k (1 ≤ k ≤ 105).

Output

Print the string Anna and Maria need — the k-th (in the lexicographical order) substring of the given string. If the total number of substrings is less than k, print a string saying "No such line." (without the quotes).

Examples

Input

aa
2


Output

a


Input

abc
5


Output

bc


Input

abab
7


Output

b

Note

In the second sample before string "bc" follow strings "a", "ab", "abc", "b".
//package practice.Impls;

import java.io.*;
import java.util.Arrays;
import java.util.Comparator;
import java.util.StringTokenizer;
import java.util.TreeMap;

public class String {
    static PrintWriter pw;
    public static void main(java.lang.String[] args) throws IOException{
        Scanner sc = new Scanner(System.in);
        pw = new PrintWriter(System.out);

        char[] s = sc.next().toCharArray();
        int k = sc.nextInt();
        if((1l*s.length*(s.length+1))/2 < k)
        {
            System.out.println("No such line.");
            return;
        }
        SA sa = new SA(s);

        sa.findLex(k);

        pw.flush();
        pw.close();
    }

    static class SA {

        int[] link, len;
        boolean[] isClone;
        TreeMap<Character, Integer>[] next;
        int lst, idx;

        SA(char[] s)
        {
            int n = s.length;
            link = new int[n<<1];
            isClone = new boolean[n<<1];
            len = new int[n<<1];
            next = new TreeMap[n<<1];
            next[0] = new TreeMap<>();
            for(char c: s)
                addLetter(c);
        }

        void addLetter(char c)
        {
            int cur = ++idx, p = lst;
            while(!next[p].containsKey(c)) { next[p].put(c, cur); p = link[p]; }

            int q = next[p].get(c);
            if(q != cur)
                if(len[q] == len[p] + 1)
                    link[cur] = q;
                else
                {
                    int clone = ++idx;
                    isClone[clone] = true;
                    len[clone] = len[p] + 1;
                    link[clone] = link[q];
                    next[clone] = new TreeMap<>(next[q]);
                    link[cur] = link[q] = clone;
                    while(next[p].get(c) == q) { next[p].put(c, clone);	p = link[p]; }
                }
            len[cur] = len[lst] + 1;
            next[cur] = new TreeMap<>();
            lst = cur;
        }




        long[] size;
        int[] cnt;
        void findLex(long k){
            vis = new boolean[idx+1];
            size = new long[link.length];
            cnt = new int[link.length];
            calcSubSize(0);
            vis[0] = true;
            calcSize(0);
            int u = 0;
            outer: while(k > 0){
                for (char c: next[u].keySet()) {
                    int v = next[u].get(c);
                    if(size[v] < k)
                        k-=size[v];
                    else
                    {
                        pw.print(c);
                        k -= cnt[v];
                        u = v;
                        continue outer;
                    }
                }
                break outer;
            }
        }

        boolean vis[];
        void calcSize(int u){
            size[u] = cnt[u];
            for (char c : next[u].keySet()) {
                int v = next[u].get(c);
                if(!vis[v]){
                    vis[v] = true;
                    calcSize(v);
                }
                size[u]+=size[v];
            }
        }

        void calcSubSize(int u){
            for (int i = 1; i < cnt.length; i++)
                if(!isClone[i])
                    cnt[i] = 1;

            Integer[] nodes = new Integer[idx+1];
            for (int i = 0; i <= idx; i++)
                nodes[i] = i;
            Arrays.sort(nodes, new Comparator<Integer>() {
                @Override
                public int compare(Integer a, Integer b) {
                    return len[b] - len[a];
                }
            });

            for (int i = 0; i < nodes.length; i++) {
                cnt[link[nodes[i]]] += cnt[nodes[i]];
            }
        }




    }



    static class Scanner
    {
        StringTokenizer st; BufferedReader br;
        public Scanner(InputStream s){	br = new BufferedReader(new InputStreamReader(s));}
        public Scanner(java.lang.String s) throws FileNotFoundException {	br = new BufferedReader(new FileReader(new File(s)));}
        public java.lang.String next() throws IOException {while (st == null || !st.hasMoreTokens()) st = new StringTokenizer(br.readLine());return st.nextToken();}
        public int nextInt() throws IOException {return Integer.parseInt(next());}
        public long nextLong() throws IOException {return Long.parseLong(next());}
        public java.lang.String nextLine() throws IOException {return br.readLine();}
        public boolean ready() throws IOException {return br.ready();}
    }


}
