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".
import java.util.*;
import java.io.*;
import java.math.BigInteger;

/**
 *
 * @author usquare
 */

public class ProblemH
{

    static long mod = (int) (1e9+7);
    static InputReader in;
    static PrintWriter out;    
    
    static int[] suffixArray(String S)
    {
        int n = S.length();
        Integer[] order = new Integer[n];
        for (int i = 0; i < n; i++)
                order[i] = n - 1 - i;
        Arrays.sort(order, (a, b) -> Character.compare(S.charAt(a), S.charAt(b)));
        int[] sa = new int[n];
        int[] classes = new int[n];
        for (int i = 0; i < n; i++)
        {
            sa[i] = order[i];
            classes[i] = S.charAt(i);
        }
        for (int len = 1; len < n; len <<= 1)
        {
            int[] c = classes.clone();
            for (int i = 0; i < n; i++)
                classes[sa[i]] = i > 0 && c[sa[i - 1]] == c[sa[i]] && sa[i - 1] + len < n
                                    && c[sa[i - 1] + (len >> 1)] == c[sa[i] + (len >> 1)] ? classes[sa[i - 1]] : i;
            int[] cnt = new int[n];
            for (int i = 0; i < n; i++)
                cnt[i] = i;
            int[] s = sa.clone();
            for (int i = 0; i < n; i++)
            {
                int s1 = s[i] - len;
                if (s1 >= 0)
                    sa[cnt[classes[s1]]++] = s1;
            }
        }
        return sa;
    }

    static int[] lcp(int[] sa, String s)
    {
        int n = sa.length;
        int[] rank = new int[n];
        for (int i = 0; i < n; i++)
            rank[sa[i]] = i;
        int[] lcp = new int[n - 1];
        
        for (int i = 0, h = 0; i < n; i++)
        {
            if (rank[i] < n - 1)
            {
                for (int j = sa[rank[i] + 1]; Math.max(i, j) + h < s.length()
                                && s.charAt(i + h) == s.charAt(j + h); ++h);
                lcp[rank[i]] = h;
                if (h > 0)
                    --h;
            }
        }
        return lcp;
    }   

    static int[] logTable;
    static int[][] rmq;

    static void rmqSparseTable(int[] a)
    {
        int n = a.length;

        logTable = new int[n + 1];
        for (int i = 2; i <= n; i++)
            logTable[i] = logTable[i >> 1] + 1;

        rmq = new int[logTable[n] + 1][n];

        for (int i = 0; i < n; ++i)
            rmq[0][i] = i;
      
        for (int k = 1; (1 << k) < n; ++k) {
            for (int i = 0; i + (1 << k) <= n; i++) {
                int x = rmq[k - 1][i];
                int y = rmq[k - 1][i + (1 << k - 1)];
                rmq[k][i] = a[x] <= a[y] ? x : y;
            }
        }
    }

    static int minPos(int i, int j, int[] a)
    {
        int k = logTable[j - i];
        int x = rmq[k][i];
        int y = rmq[k][j - (1 << k) + 1];
        return a[x] <= a[y] ? x : y;
    }
    
    static void solve() 
    {

        in = new InputReader(System.in);
        out = new PrintWriter(System.out);
       
        String s = in.readString();
        int n = s.length();
        int k = in.nextInt();
        
        int[] sa = suffixArray(s);
        int[] lcp = lcp(sa, s);
        
        rmqSparseTable(lcp);
        String ans = "";
        int j = 0;
        while(j < n){
            for(int i = (j == 0) ? 1 : lcp[j - 1] + 1; i <= n - sa[j]; i++){
                int l = j;
                int r = n - 2;
                int ind = j - 1;
                while(r >= l){
                    int mid = (l + r) >> 1;
                    if(lcp[minPos(j, mid, lcp)] >= i){
                        ind = mid;
                        l = mid + 1;
                    }
                    else r = mid - 1;
                }
                k -= ind - j + 2;
                if(k <= 0){
                    ans = s.substring(sa[j],sa[j] + i );
                    break;
                }
            }
            if(k <= 0) break;
            j++;
        }
        if(ans.equals("")) ans = "No such line.";
        out.println(ans);
        out.close();

    }
    
    
    public static void main(String[] args)
    {

        new Thread(null,new Runnable()
        {
            @Override
            public void run()
            {
                try{
                    solve();
                }
                catch(Exception e){
                    e.printStackTrace();
                }
            }
        },"1",1<<26).start();
    }

    static class Pair implements Comparable<Pair>
    {

        int x,y;
        int i;
        
	Pair (int x,int y,int i)
        {
		this.x = x;
		this.y = y;
                this.i = i;
	}
        
        Pair (int x,int y)
        {
		this.x = x;
		this.y = y;
	}
        
	public int compareTo(Pair o)
        {
            if(this.x != o.x)
                    return Integer.compare(this.x,o.x);
            return Integer.compare(this.y, o.y);
		//return 0;
	}

        public boolean equals(Object o)
        {
            if (o instanceof Pair)
            {
                Pair p = (Pair)o;
                return p.x == x && p.y==y;
            }
            return false;
        }

        @Override
        public String toString()
        {
            return x + " "+ y + " "+i;
        }
        
        public int hashCode()
        {
            return new Integer(x).hashCode() * 31 + new Integer(y).hashCode();
        }
    
    } 


    static class Merge
    {

        public static void sort(int inputArr[])
        {
            int length = inputArr.length;
            doMergeSort(inputArr,0, length - 1);
        }

        private static void doMergeSort(int[] arr,int lowerIndex, int higherIndex)
        {        
            if (lowerIndex < higherIndex)
            {
                int middle = lowerIndex + (higherIndex - lowerIndex) / 2;
                doMergeSort(arr,lowerIndex, middle);
                doMergeSort(arr,middle + 1, higherIndex);
                mergeParts(arr,lowerIndex, middle, higherIndex);
            }
        }

        private static void mergeParts(int[]array,int lowerIndex, int middle, int higherIndex)
        {
            int[] temp=new int[higherIndex-lowerIndex+1];
            for (int i = lowerIndex; i <= higherIndex; i++)
            {
                temp[i-lowerIndex] = array[i];
            }
            int i = lowerIndex;
            int j = middle + 1;
            int k = lowerIndex;
            while (i <= middle && j <= higherIndex)
            {
                if (temp[i-lowerIndex] < temp[j-lowerIndex])
                {
                    array[k] = temp[i-lowerIndex];
                    i++;
                } else
                {
                    array[k] = temp[j-lowerIndex];
                    j++;
                }
                k++;
            }
            while (i <= middle)
            {
                array[k] = temp[i-lowerIndex];
                k++;
                i++;
            }
            while(j<=higherIndex)
            {
                array[k]=temp[j-lowerIndex];
                k++;
                j++;
            }
        }

    }

    static long add(long a,long b)
    {
        long x=(a+b);
        while(x>=mod) x-=mod;
        return x;
    }

    static long sub(long a,long b)
    {
        long x=(a-b);
        while(x<0) x+=mod;
        return x;
    }

    static long mul(long a,long b)
    {
        a%=mod;
        b%=mod;
        long x=(a*b);
        return x%mod;
    }


    static boolean isPal(String s)
    {
        for(int i=0, j=s.length()-1;i<=j;i++,j--)
        {
                if(s.charAt(i)!=s.charAt(j)) return false;
        }
        return true;
    }
    static String rev(String s)
    {
                StringBuilder sb=new StringBuilder(s);
                sb.reverse();
                return sb.toString();
    }

    static long gcd(long x,long y)
    {
        if(y==0)
                return x;
        else
                return gcd(y,x%y);
    }

    static int gcd(int x,int y)
    {
        if(y==0)
                return x;
        else 
                return gcd(y,x%y);
    }

    static long gcdExtended(long a,long b,long[] x)
    {

        if(a==0)
        {
            x[0]=0;
            x[1]=1;
            return b;
        }
        long[] y=new long[2];
        long gcd=gcdExtended(b%a, a, y);

        x[0]=y[1]-(b/a)*y[0];
        x[1]=y[0];

        return gcd;
    }


    static long mulmod(long  a,long b,long m)
    {
        if (m <= 1000000009) return a * b % m;

        long res = 0;
        while (a > 0)
        {
            if ((a&1)!=0)
            {
                res += b;
                if (res >= m) res -= m;
            }
            a >>= 1;
            b <<= 1;
            if (b >= m) b -= m;
        }
        return res;
    }

    static int abs(int a,int b)
    {
        return (int)Math.abs(a-b);
    }

    public static long abs(long a,long b)
    {
        return (long)Math.abs(a-b);
    }

    static int max(int a,int b)
    {
        if(a>b)
                return a;
        else
                return b;
    }

    static int min(int a,int b)
    {
        if(a>b)
                return b;
        else 
                return a;
    }

    static long max(long a,long b)
    {
        if(a>b)
                return a;
        else
                return b;
    }

    static long min(long a,long b)
    {
        if(a>b)
                return b;
        else 
                return a;
    }

    static long pow(long n,long p,long m)
    {
         long  result = 1;
          if(p==0)
            return 1;

        while(p!=0)
        {
            if(p%2==1)
                result *= n;
            if(result>=m)
            result%=m;
            p >>=1;
            n*=n;
            if(n>=m)
            n%=m;
        }
        return result;
    }

    static long pow(long n,long p)
    {
        long  result = 1;
          if(p==0)
            return 1;

        while(p!=0)
        {
            if(p%2==1)
                result *= n;	    
            p >>=1;
            n*=n;	    
        }
        return result;
    }

    static void debug(Object... o)
    {
            System.out.println(Arrays.deepToString(o));
    }

    static class InputReader
    {

        private final InputStream hasheam;
        private final byte[] buf = new byte[8192];
        private int curChar, snumChars;
        private SpaceCharFilter filter;

        public InputReader(InputStream hasheam)
        {
                this.hasheam = hasheam;
        }

        public int snext()
        {
                if (snumChars == -1)
                        throw new InputMismatchException();
                if (curChar >= snumChars)
                {
                        curChar = 0;
                        try
                        {
                                snumChars = hasheam.read(buf);
                        } catch (IOException e)
                        {
                                throw new InputMismatchException();
                        }
                        if (snumChars <= 0)
                                return -1;
                }
                return buf[curChar++];
        }

        public int nextInt()
        {
                int c = snext();
                while (isSpaceChar(c))
                {
                        c = snext();
                }
                int sgn = 1;
                if (c == '-')
                {
                        sgn = -1;
                        c = snext();
                }
                int res = 0;
                do
                {
                        if (c < '0' || c > '9')
                                throw new InputMismatchException();
                        res *= 10;
                        res += c - '0';
                        c = snext();
                } while (!isSpaceChar(c));
                return res * sgn;
        }

        public long nextLong()
        {
                int c = snext();
                while (isSpaceChar(c))
                {
                        c = snext();
                }
                int sgn = 1;
                if (c == '-')
                {
                        sgn = -1;
                        c = snext();
                }
                long res = 0;
                do
                {
                        if (c < '0' || c > '9')
                                throw new InputMismatchException();
                        res *= 10;
                        res += c - '0';
                        c = snext();
                } while (!isSpaceChar(c));
                return res * sgn;
        }

        public int[] nextIntArray(int n)
        {
                int a[] = new int[n];
                for (int i = 0; i < n; i++)
                {
                        a[i] = nextInt();
                }
                return a;
        }

        public long[] nextLongArray(int n)
        {
                long a[] = new long[n];
                for (int i = 0; i < n; i++)
                {
                        a[i] = nextLong();
                }
                return a;
        }

        public String readString()
        {
                int c = snext();
                while (isSpaceChar(c))
                {
                        c = snext();
                }
                StringBuilder res = new StringBuilder();
                do
                {
                        res.appendCodePoint(c);
                        c = snext();
                } while (!isSpaceChar(c));
                return res.toString();
        }

        public String nextLine()
        {
                int c = snext();
                while (isSpaceChar(c))
                        c = snext();
                StringBuilder res = new StringBuilder();
                do
                {
                        res.appendCodePoint(c);
                        c = snext();
                } while (!isEndOfLine(c));
                return res.toString();
        }

        public boolean isSpaceChar(int c)
        {
                if (filter != null)
                        return filter.isSpaceChar(c);
                return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        private boolean isEndOfLine(int c)
        {
                return c == '\n' || c == '\r' || c == -1;
        }

        public interface SpaceCharFilter
        {
                public boolean isSpaceChar(int ch);
        }

    }
}    
