1310_C. Au Pont Rouge_16249
VK just opened its second HQ in St. Petersburg! Side of its office building has a huge string s written on its side. This part of the office is supposed to be split into m meeting rooms in such way that meeting room walls are strictly between letters on the building. Obviously, meeting rooms should not be of size 0, but can be as small as one letter wide. Each meeting room will be named after the substring of s written on its side.

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For each possible arrangement of m meeting rooms we ordered a test meeting room label for the meeting room with lexicographically minimal name. When delivered, those labels got sorted backward lexicographically.

What is printed on kth label of the delivery?

Input

In the first line, you are given three integer numbers n, m, k — length of string s, number of planned meeting rooms to split s into and number of the interesting label (2 ≤ n ≤ 1 000; 1 ≤ m ≤ 1 000; 1 ≤ k ≤ 10^{18}).

Second input line has string s, consisting of n lowercase english letters.

For given n, m, k there are at least k ways to split s into m substrings.

Output

Output single string – name of meeting room printed on k-th label of the delivery.

Examples

Input


4 2 1
abac


Output


aba


Input


19 5 1821
aupontrougevkoffice


Output


au

Note

In the first example, delivery consists of the labels "aba", "ab", "a".

In the second example, delivery consists of 3060 labels. The first label is "aupontrougevkof" and the last one is "a".
import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.FileNotFoundException;
import java.util.StringTokenizer;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        FastScanner in = new FastScanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        CKrasniiMost solver = new CKrasniiMost();
        solver.solve(1, in, out);
        out.close();
    }

    static class CKrasniiMost {
        long MAX = (long) 1e18;
        int n;
        int m;
        char[] s;
        int[][] lcp;

        int cmp(int l1, int r1, int l2, int r2) {
            int l = lcp[l1][l2];
            if (l1 + l > r1 || l2 + l > r2) {
                return (r1 - l1) - (r2 - l2);
            } else {
                return s[l1 + l] - s[l2 + l];
            }
        }

        public void solve(int testNumber, FastScanner in, PrintWriter out) {
            n = in.nextInt();
            m = in.nextInt();
            long k = in.nextLong();
            s = in.next().toCharArray();
            lcp = new int[n][n];
            for (int i = n - 1; i >= 0; i--) {
                for (int j = n - 1; j >= 0; j--) {
                    if (s[i] != s[j]) {
                        lcp[i][j] = 0;
                    } else {
                        lcp[i][j] = 1;
                        if (i + 1 < n && j + 1 < n) {
                            lcp[i][j] += lcp[i + 1][j + 1];
                        }
                    }
                }
            }

            Substr[] all = new Substr[n * (n + 1) / 2];
            int ptr = 0;
            for (int i = 0; i < n; i++) {
                for (int j = i; j < n; j++) {
                    all[ptr++] = new Substr(i, j);
                }
            }
            Arrays.sort(all);
            long[][] dp = new long[m + 1][n + 1];

            int left = -1, right = all.length - 1;
            while (left < right - 1) {
                int mid = (left + right) >>> 1;

                int cmpL = all[mid].l, cmpR = all[mid].r;
                int cmpLen = cmpR - cmpL;
                for (int i = 0; i <= m; i++) {
                    Arrays.fill(dp[i], 0);
                }
                dp[0][0] = 1;
                dp[0][1] = -1;
                for (int cnt = 0; cnt < m; cnt++) {
                    long cur = 0;
                    long[] prevDP = dp[cnt], nextDP = dp[cnt + 1];
                    for (int i = 0; i < n; i++) {
                        cur += prevDP[i];
                        if (cur > MAX) {
                            cur = MAX;
                        }
                        if (cur == 0) {
                            continue;
                        }
                        int l = lcp[i][cmpL];
                        if (cmpL + l > cmpR) {
                            // add on segment i + cmpLen + 1 .. n
                            nextDP[i + cmpLen + 1] += cur;
                            if (nextDP[i + cmpLen + 1] >= MAX) {
                                nextDP[i + cmpLen + 1] = MAX;
                            }
                        } else {
                            if (i + l < n && s[cmpL + l] < s[i + l]) {
                                // add on segment i + l + 1 .. n
                                nextDP[i + l + 1] += cur;
                                if (nextDP[i + l + 1] >= MAX) {
                                    nextDP[i + l + 1] = MAX;
                                }
                            }
                        }
                    }
                }

                long cur = 0;
                for (int i = 0; i <= n; i++) {
                    cur = Math.min(MAX, cur + dp[m][i]);
                }
                if (cur >= k) {
                    right = mid;
                } else {
                    left = mid;
                }
            }

            for (int i = all[right].l; i <= all[right].r; i++) {
                out.print(s[i]);
            }
            out.println();
        }

        class Substr implements Comparable<Substr> {
            int l;
            int r;

            public Substr(int l, int r) {
                this.l = l;
                this.r = r;
            }

            public int compareTo(Substr substr) {
                return -cmp(l, r, substr.l, substr.r);
            }

            public String toString() {
                return "Substr{" +
                        "l=" + l +
                        ", r=" + r +
                        '}';
            }

        }

    }

    static class FastScanner {
        public BufferedReader br;
        public StringTokenizer st;

        public FastScanner(InputStream in) {
            br = new BufferedReader(new InputStreamReader(in));
        }

        public FastScanner(String fileName) {
            try {
                br = new BufferedReader(new FileReader(fileName));
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            }
        }

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

        public String next() {
            while (st == null || !st.hasMoreElements()) {
                String line = null;
                try {
                    line = br.readLine();
                } catch (IOException e) {
                }
                st = new StringTokenizer(line);
            }
            return st.nextToken();
        }

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

    }
}

