The numbers 1,   2,   ...,   n ⋅ k are colored with n colors. These colors are indexed by 1,   2,   ...,   n. For each 1 ≤ i ≤ n, there are exactly k numbers colored with color i.

Let [a,   b] denote the interval of integers between a and b inclusive, that is, the set \\{a,   a + 1,   ...,   b\}. You must choose n intervals [a_1,   b_1],   [a_2,   b_2],   ..., [a_n,   b_n] such that: 

  * for each 1 ≤ i ≤ n, it holds 1 ≤ a_i < b_i ≤ n ⋅ k; 
  * for each 1 ≤ i ≤ n, the numbers a_i and b_i are colored with color i; 
  * each number 1 ≤ x ≤ n ⋅ k belongs to at most \left⌈ (n)/(k - 1) \right⌉ intervals. 



One can show that such a family of intervals always exists under the given constraints.

Input

The first line contains two integers n and k (1 ≤ n ≤ 100, 2 ≤ k ≤ 100) — the number of colors and the number of occurrences of each color.

The second line contains n ⋅ k integers c_1,   c_2,   ...,   c_{nk} (1 ≤ c_j ≤ n), where c_j is the color of number j. It is guaranteed that, for each 1 ≤ i ≤ n, it holds c_j = i for exactly k distinct indices j.

Output

Output n lines. The i-th line should contain the two integers a_i and b_i.

If there are multiple valid choices of the intervals, output any.

Examples

Input


4 3
2 4 3 1 1 4 2 3 2 1 3 4


Output


4 5
1 7
8 11
6 12

Input


1 2
1 1


Output


1 2


Input


3 3
3 1 2 3 2 1 2 1 3


Output


6 8
3 7
1 4

Input


2 3
2 1 1 1 2 2


Output


2 3
5 6

Note

In the first sample, each number can be contained in at most \left⌈ (4)/(3 - 1) \right⌉ = 2 intervals. The output is described by the following picture:

<image>

In the second sample, the only interval to be chosen is forced to be [1,   2], and each number is indeed contained in at most \left⌈ (1)/(2 - 1) \right⌉ = 1 interval.

In the third sample, each number can be contained in at most \left⌈ (3)/(3 - 1) \right⌉ = 2 intervals. The output is described by the following picture:

<image>
import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Objects;
import java.util.Arrays;
import java.util.Map;
import java.util.HashMap;
import java.util.InputMismatchException;
import java.io.IOException;
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;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        ETsvetaIOtrezki solver = new ETsvetaIOtrezki();
        solver.solve(1, in, out);
        out.close();
    }

    static class ETsvetaIOtrezki {
        public void solve(int testNumber, InputReader in, PrintWriter out) {
            int n = in.nextInt();
            int k = in.nextInt();
            int[] a = new int[n * k];

            int m = (n + k - 2) / (k - 1);

            int[] prev = new int[n];
            int[] ct = new int[n * k];

            Arrays.fill(prev, -1);
            Map<Integer, Pair<Integer, Integer>> ans = new HashMap<>();


            for (int i = 0; i < n * k; i++) {
                int val = in.nextInt() - 1;
                if (prev[val] != -1 && !ans.containsKey(val)) {
                    int max = Integer.MIN_VALUE;

                    for (int h = prev[val]; h <= i; h++) {
                        ct[h]++;
                        max = Math.max(max, ct[h]);
                    }
                    if (max <= m) {
                        ans.put(val, Pair.of(prev[val], i));
                    } else {
                        for (int h = prev[val]; h <= i; h++) {
                            ct[h]--;
                        }
                    }
                }
                prev[val] = i;
            }
            for (int i = 0; i < n; i++) {
                Pair<Integer, Integer> p = ans.get(i);
                out.println((p.fs + 1) + " " + (p.sc + 1));
            }
        }

    }

    static class InputReader {
        private static final int BUFFER_LENGTH = 1 << 10;
        private InputStream stream;
        private byte[] buf = new byte[BUFFER_LENGTH];
        private int curChar;
        private int numChars;

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

        private int nextC() {
            if (numChars == -1) {
                throw new InputMismatchException();
            }
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0)
                    return -1;
            }
            return buf[curChar++];
        }

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

        public int skipWhileSpace() {
            int c = nextC();
            while (isSpaceChar(c)) {
                c = nextC();
            }
            return c;
        }

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

    }

    static class Pair<T, K> {
        T fs;
        K sc;

        public Pair(T fs, K sc) {
            this.fs = fs;
            this.sc = sc;
        }

        public static <T, K> Pair<T, K> of(T fs, K sc) {
            return new Pair<>(fs, sc);
        }

        public boolean equals(Object o) {
            if (this == o) {
                return true;
            }
            if (o == null || getClass() != o.getClass()) {
                return false;
            }
            Pair<?, ?> pair = (Pair<?, ?>) o;
            return Objects.equals(fs, pair.fs) && Objects.equals(sc, pair.sc);
        }

        public int hashCode() {
            return Objects.hash(fs, sc);
        }

    }
}

