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:
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.math.BigInteger;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.StringTokenizer;

public class Solution implements Runnable
{
    private void solve() throws IOException
    {
    	
    	int n = nextInt();
    	
    	long[]array = new long[n];
    	for (int i = 0; i < n; i++) {
    		array[i] = nextLong();
    	}
    	
    	if (n == 1) {
    		writer.print("");
    		return;
    	}
    	
    	int i = 0;
    	boolean isSorted = false;
    	while (true) {
    		if (array[i] > array[i+1]) {
    			isSorted = false;
    			long temp = array[i];
    			array[i] = array[i+1];
    			array[i+1] = temp;
    			
    	    	writer.println((i+1) + " " + (i+2));
    			
    			i+=2;
    		}
    		else 
    			i++;
    		
    		if (i >= n-1)
    			if (isSorted)
    				break;
    			else {
    	    		isSorted = true;
    				i = 0;
    			}
    	}
    	   
    	
    }
    
    private boolean isPowerOfTwo(long x) {
        return (x != 0) && ((x & (x - 1)) == 0);
    }
    
    private int exponentOfTwo(long n) {
    	return (int)( Math.floor(Math.log(n) / Math.log(2)));

    }

    private Long sumDiagLR (Long[][] array) {
        long sum = 0;
        int i = 0, j = 0;

        while (i < array.length && j < array.length) {
            sum += array[i][j];
            i++;
            j++;
        }

        return sum;
    }

    private Long sumDiagRL (Long[][] array) {
       long sum = 0;
       int i = array.length-1, j = 0;

       while (i >=0 && j < array.length) {
           sum += array[i][j];
           i--;
           j++;
       }

       return sum;
   }


    private BigInteger factorial( String n )
    {
        BigInteger k = new BigInteger( n );
        BigInteger ans = BigInteger.ONE;

        while ( k.compareTo( BigInteger.ONE ) > 0 )
        {
            ans = ans.multiply( k );
            k = k.subtract( BigInteger.ONE );
        }

        return ans;
    }

    private long combinations( int n, int r )
    {
        return ( factorial( String.valueOf( n ) ).divide( ( new BigInteger( String.valueOf( r ) ).multiply( factorial( String.valueOf( n - r ) ) ) ) ) ).longValue();
    }


    private String binaryXOR( String s1, String s2 )
    {
        BigInteger a = new BigInteger( s1, 2 );
        BigInteger b = new BigInteger( s2, 2 );

        return a.xor( b ).toString( 2 );

    }


    private static void findDP( Node node )
    {
        for ( Node child : node.children )
        {
            if ( child.value > node.value )
            {
                child.dp = Math.max( child.dp, node.dp + 1 );
                //findDP( child );
            }
        }
    }

    private static class Obj implements Comparable<Obj>
    {
        String name;
        int value;

        public Obj( int value )
        {
            this.value = value;
        }

        public Obj( String name, int value )
        {
            this.name = name;
            this.value = value;
        }

        @Override
        public int compareTo( Obj o )
        {
            return o.value - this.value;
        }
    }


    private static class Edge
    {
        PNode src;
        PNode des;
        long cost;

        public Edge (PNode src, PNode des, long cost) {
            this.src = src;
            this.des = des;
            this.cost = cost;
        }
    }

    private static class PNode
    {
        List<Edge> edges;
        long value;
        boolean isTrue;

        public PNode() {
            this.edges = new ArrayList<>(  );
            this.isTrue = false;
        }

        public PNode(long value ) {
           this.edges = new ArrayList<>(  );
           this.isTrue = false;
            this.value = value;
       }
    }

    private static class Node
    {
        long value;
        long dp;
        List<Node> children;
        Node parent;

        public  Node(){};

        public Node( int value )
        {
            this.value = value;
            dp = 1;
            children = new ArrayList<Node>();
        }
    }

    private static boolean isInt( String s )
    {
        if ( s.length() < 1 )
            return false;
        else
        {
            for ( char c : s.toCharArray() )
            {
                if ( c < '0' || c > '9' )
                {
                    return false;
                }
            }
        }

        return true;
    }

    private static Map<String, Integer> findSubString( String s, int k )
    {
        Map<String, Integer> map = new HashMap<>();
        for ( int i = 0; i < s.length() - ( k - 1 ); i++ )
        {
            String str = new String( s.substring( i, i + k ) );
            if ( map.containsKey( str ) )
            {
                map.put( str, map.get( str ) + 1 );
            }
            else
            {
                map.put( str, 1 );

            }
        }

        return map;
    }


    //mergesort

    public static Comparable[] mergeSort( Comparable[] list )
    {
        if ( list.length <= 1 )
        {
            return list;
        }

        Comparable[] left = new Comparable[ list.length / 2 ];
        Comparable[] right = new Comparable[ list.length - left.length ];
        System.arraycopy( list, 0, left, 0, left.length );
        System.arraycopy( list, left.length, right, 0, right.length );

        mergeSort( left );
        mergeSort( right );

        merge( left, right, list );
        return list;
    }

    private static void merge( Comparable[] left, Comparable[] right, Comparable[] result )
    {
        int leftIdx = 0;
        int rightIdx = 0;
        int index = 0;

        while ( leftIdx < left.length && rightIdx < right.length )
        {
            if ( left[ leftIdx ].compareTo( right[ rightIdx ] ) < 0 )
            {
                result[ index++ ] = left[ leftIdx ];
                leftIdx++;
            }
            else
            {
                result[ index++ ] = right[ rightIdx ];
                rightIdx++;
            }
        }

        System.arraycopy( left, leftIdx, result, index, left.length - leftIdx );
        System.arraycopy( right, rightIdx, result, index, right.length - rightIdx );
    }

    public static List<Obj> mergeSort( List<Obj> list )
    {
        if ( list.size() <= 1 )
        {
            return list;
        }

        List<Obj> left = new ArrayList( list.subList( 0, list.size() / 2 ) );
        List<Obj> right = new ArrayList( list.subList( left.size(), list.size() ) );

        left = mergeSort( left );
        right = mergeSort( right );

        list = merge( left, right );

        return list;
    }

    private static List<Obj> merge( List<Obj> left, List<Obj> right )
    {
        int leftCounter = 0, rightCounter = 0;
        List<Obj> result = new ArrayList<>();

        while ( leftCounter < left.size() && rightCounter < right.size() )
        {
            Obj leftItem = left.get( leftCounter );
            Obj rightItem = right.get( rightCounter );

            if ( leftItem.compareTo( rightItem ) < 0 )
            {
                result.add( leftItem );
                leftCounter++;
            }
            else
            {
                result.add( rightItem );
                rightCounter++;
            }
        }

        if ( leftCounter >= left.size() )
            result.addAll( right.subList( rightCounter, right.size() ) );
        else if ( rightCounter >= right.size() )
            result.addAll( left.subList( leftCounter, left.size() ) );

        return result;
    }

    public static void main( String[] args )
    {
        new Solution().run();
    }

    BufferedReader reader;
    StringTokenizer tokenizer;
    PrintWriter writer;

    public void run()
    {
        try
        {
            reader = new BufferedReader( new InputStreamReader( System.in ) );
            tokenizer = null;
            writer = new PrintWriter( System.out );
            solve();
            reader.close();
            writer.close();
        }
        catch ( Exception e )
        {
            e.printStackTrace();
            System.exit( 1 );
        }
    }

    int nextInt() throws IOException
    {
        return Integer.parseInt( nextToken() );
    }

    long nextLong() throws IOException
    {
        return Long.parseLong( nextToken() );
    }

    double nextDouble() throws IOException
    {
        return Double.parseDouble( nextToken() );
    }

    String nextToken() throws IOException
    {
        while ( tokenizer == null || !tokenizer.hasMoreTokens() )
        {
            tokenizer = new StringTokenizer( reader.readLine() );
        }
        return tokenizer.nextToken();
    }

    // Arrays.sort(array, Comparator.comparing((int[] arr) -> arr[1]));
}