Problem: Little Robber Girl likes to scare animals in her zoo for fun. She decided to arrange the animals in a row in the order of non-decreasing height. However, the animals were so scared that they couldn't stay in the right places.

The robber girl was angry at first, but then she decided to arrange the animals herself. She repeatedly names numbers l and r such that r - l + 1 is even. After that animals that occupy positions between l and r inclusively are rearranged as follows: the animal at position l swaps places with the animal at position l + 1, the animal l + 2 swaps with the animal l + 3, ..., finally, the animal at position r - 1 swaps with the animal r.

Help the robber girl to arrange the animals in the order of non-decreasing height. You should name at most 20 000 segments, since otherwise the robber girl will become bored and will start scaring the animals again.

Input

The first line contains a single integer n (1 ≤ n ≤ 100) — number of animals in the robber girl's zoo.

The second line contains n space-separated integers a1, a2, ..., an (1 ≤ ai ≤ 109), where ai is the height of the animal occupying the i-th place.

Output

Print the sequence of operations that will rearrange the animals by non-decreasing height.

The output should contain several lines, i-th of the lines should contain two space-separated integers li and ri (1 ≤ li < ri ≤ n) — descriptions of segments the robber girl should name. The segments should be described in the order the operations are performed.

The number of operations should not exceed 20 000.

If the animals are arranged correctly from the start, you are allowed to output nothing.

Examples

Input

4
2 1 4 3


Output

1 4


Input

7
36 28 57 39 66 69 68


Output

1 4
6 7


Input

5
1 2 1 2 1


Output

2 5
3 4
1 4
1 4

Note

Note that you don't have to minimize the number of operations. Any solution that performs at most 20 000 operations is allowed.

Solution (in JAVA):

Solution:
/**
 * Created by ankeet on 6/23/16.
 */
import java.io.*;
import java.util.*;
import java.math.*;

public class B686 {

    public static BufferedReader read = null;
    public static PrintWriter out = null;
    public static StringTokenizer token = null;


    public static void solve()
    {
        int n = nint();
        int[] a = narr(n);
        for(int i=0; i<n-1; i++)
        {
            int min = Integer.MAX_VALUE, minl = -1;
            for(int j=i; j<n; j++)
            {
                if(a[j] < min)
                {
                    min = a[j];
                    minl = j;
                }
            }

            // get position minl to position i
            while(minl != i)
            {
                out.println((minl-1+1) + " " + (minl+1));
                int temp = a[minl];
                a[minl] = a[minl-1];
                a[minl-1] = temp;
                minl--;
            }
        }
    }

    public static void main(String[] args)
    {
        read = new BufferedReader(new InputStreamReader(System.in));
        out = new PrintWriter(System.out);
        solve();
        out.flush();
        out.close();

    }

    // i/o functions
    public static String next() // returns the next string
    {
        while(token == null || !token.hasMoreTokens())
        {
            try {
                token = new StringTokenizer(read.readLine());
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        return token.nextToken();
    }

    public static int nint()
    {
        return Integer.parseInt(next());
    }
    public static long nlong()
    {
        return Long.parseLong(next());
    }
    public static double ndouble()
    {
        return Double.parseDouble(next());
    }
    public static int[] narr(int n)
    {
        int[] a = new int[n];
        for(int i=0; i<n; i++) a[i] = nint();
        return a;
    }

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


}