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:
// All important imports 
import static java.lang.System.in;

import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.DataInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.lang.reflect.Array;
import java.math.BigInteger;
import java.text.DecimalFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.BitSet;
import java.util.Collections;
import java.util.Comparator;
import java.util.Date;
import java.util.Deque;
import java.util.GregorianCalendar;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Hashtable;
import java.util.InputMismatchException;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.PriorityQueue;
import java.util.Stack;
import java.util.Queue;
import java.util.Random;
import java.util.StringTokenizer;
import java.util.TreeMap;
import java.util.Vector;

public class Main {

	public static void solve() {
		int n = ni();
		int arr[] =nia(n);
		for(int i=0;i<n;i++){
			for(int j=0;j<n-i-1;j++){
				if(arr[j]>arr[j+1]){
					int temp=arr[j+1];
					arr[j+1]=arr[j];
					arr[j]=temp;
					out.println((1+j)+" "+(j+2));
				}
			}
		}

	}

	// END OF SOLUTION
	// INPUT OUTPUT TEMPLATE
	static String TESTCASES;
	static PrintWriter out;

	public static void main(String[] args) throws Exception, IOException {
		out = new PrintWriter(System.out);
		InputStream myinp = System.in;
		init(myinp);
		// int t=ni();
		// int i=1;
		// while(t-->0)
		{
			solve();
		}
		out.close();

	}

	static InputStream is;
	static BufferedReader brr;
	static int BUFFER_SIZE = 65000;
	static DataInputStream din;
	static byte[] buffer;
	static int bufferPointer, bytesRead;

	public static void init(InputStream input) {
		is = input;
		brr = new BufferedReader(new InputStreamReader(input));
		din = new DataInputStream(in);
		buffer = new byte[BUFFER_SIZE];
		bufferPointer = bytesRead = 0;
	}

	protected static byte[] inbuf = new byte[1024];
	static int lenbuf = 0, ptrbuf = 0;

	static byte read() throws Exception {
		if (bufferPointer == bytesRead)
			fillBuffer();
		return buffer[bufferPointer++];
	}

	protected static int readByte() {
		if (lenbuf == -1)
			throw new InputMismatchException();
		if (ptrbuf >= lenbuf) {
			ptrbuf = 0;
			try {
				lenbuf = is.read(inbuf);
			} catch (IOException e) {
				throw new InputMismatchException();
			}
			if (lenbuf <= 0)
				return -1;
		}
		return inbuf[ptrbuf++];
	}

	protected static String readline() throws IOException {
		return brr.readLine();
	}

	// extras
	protected static double nd() {
		return Double.parseDouble(ns());
	}

	protected static char nc() {
		return (char) skip();
	}

	protected static boolean isSpaceChar(int c) {
		return !(c >= 33 && c <= 126);
	}

	protected static int skip() {
		int b;
		while ((b = readByte()) != -1 && isSpaceChar(b))
			;
		return b;
	}

	static void fillBuffer() throws Exception {
		bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE);
		if (bytesRead == -1)
			buffer[0] = -1;
	}

	protected static String ns() {
		int b = skip();
		StringBuilder sb = new StringBuilder();
		while (!(isSpaceChar(b))) { // when nextLine, (isSpaceChar(b) && b !=
									// ' ')
			sb.appendCodePoint(b);
			b = readByte();
		}
		return sb.toString();
	}

	protected static char[] nca(int n) {
		char[] buf = new char[n];
		int b = skip(), p = 0;
		while (p < n && !(isSpaceChar(b))) {
			buf[p++] = (char) b;
			b = readByte();
		}
		return n == p ? buf : Arrays.copyOf(buf, p);
	}

	protected static int[] nia(int n) {
		int[] a = new int[n];
		for (int i = 0; i < n; i++)
			a[i] = ni();
		return a;
	}

	protected static int[][] niaindex(int n) {
		int ea[][] = new int[n][2];
		for (int i = 0; i < n; i++) {
			ea[i][0] = ni();
			ea[i][1] = i;
		}
		return ea;
	}

	protected static long[] nla(int n) {
		long[] a = new long[n];
		for (int i = 0; i < n; i++)
			a[i] = nl();
		return a;
	}

	protected static long[][] nlaindex(int n) {
		long ea[][] = new long[n][2];
		for (int i = 0; i < n; i++) {
			ea[i][0] = ni();
			ea[i][1] = i;
		}
		return ea;
	}

	protected static String[] nsa(int n) {
		String[] a = new String[n];
		for (int i = 0; i < n; i++)
			a[i] = ns();
		return a;
	}

	protected static double[] nda(int n) {
		double[] a = new double[n];
		for (int i = 0; i < n; i++)
			a[i] = nd();
		return a;
	}

	static int ni2() throws Exception {
		int ret = 0;
		byte c = read();
		while (c <= ' ')
			c = read();
		boolean neg = c == '-';
		if (neg)
			c = read();
		do {
			ret = ret * 10 + c - '0';
			c = read();
		} while (c > ' ');
		if (neg)
			return -ret;
		return ret;

	}

	protected static int ni() {
		int num = 0, b;
		boolean minus = false;
		while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'))
			;
		if (b == '-') {
			minus = true;
			b = readByte();
		}

		while (true) {
			if (b >= '0' && b <= '9') {
				num = num * 10 + (b - '0');
			} else {
				return minus ? -num : num;
			}
			b = readByte();
		}
	}

	protected static long nl() {
		long num = 0;
		int b;
		boolean minus = false;
		while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'))
			;
		if (b == '-') {
			minus = true;
			b = readByte();
		}

		while (true) {
			if (b >= '0' && b <= '9') {
				num = num * 10 + (b - '0');
			} else {
				return minus ? -num : num;
			}
			b = readByte();
		}
	}

	// Outputs
	public static void pln() {
		out.println();
	}

	public static void ps(String s) {
		out.print(s);
	}

	public static void pi(int s) {
		out.print(s);
	}

	public static void pl(long s) {
		out.print(s);
	}

	public static void pd(double s) {
		out.print(s);
	}

	public static void psp() {
		out.print(" ");
	}

	public static void parr(int s[]) {
		out.println(Arrays.toString(s));
	}

	public static void parr(String s[]) {
		out.println(Arrays.toString(s));
	}

	public static void parr(long s[]) {
		out.println(Arrays.toString(s));
	}

	public static void parr2(int s[][]) {
		for (int i = 0; i < s.length; i++)
			out.println(Arrays.toString(s[i]));
	}

	public static void parr2(long s[][]) {
		for (int i = 0; i < s.length; i++)
			out.println(Arrays.toString(s[i]));
	}

	public static void parr2(String s[][]) {
		for (int i = 0; i < s.length; i++)
			out.println(Arrays.toString(s[i]));
	}

}