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.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.Writer;
import java.util.*;


public class B
{
    public static void main(String[] args) throws Exception
    {
    	int n=i();
    	int[] a = new int[n];
    	Iarr(a, n);
    	for( int i=0 ; i<n-1 ; i++ )
    	{
    		if( a[i]>a[i+1] )
    		{
    			out.println((i+1)+" "+(i+2));
    			int te=a[i];
    			a[i]=a[i+1];
    			a[i+1]=te;
    			int j=i;
    			while( j>0 )
    			{
    				if( a[j-1]>a[j] )
    				{
    					te=a[j];
    	    			a[j]=a[j-1];
    	    			a[j-1]=te;
    	    			out.println((j)+" "+(j+1));
    				}
    				else
    					break;
    				j--;
    			}
    			i=j;
    		}
    	}
        out.close();
        
    }
    
    static boolean check( int[] a )
    {
    	int n=a.length;
    	for( int i=0 ; i<n-1 ; i++ )
    	{
    		if( a[i]>a[i+1] ) return true;
    	}
    	return false;
    }
    
    public static ArrayList<Long> primeFactors(long n) {
        ArrayList<Long> factors = new ArrayList<Long>();
        for (long i = 2; i <= n / i; i++) {
            while (n % i == 0) {
                factors.add(i);
                n /= i;
            }
        }
        if (n > 1) {
            factors.add(n);
        }
        return factors;
    }
 
    public static HashSet<Long> uniquePrimeFactors(long n) {
        return new HashSet<Long>(primeFactors(n));
    }

    
    static long gcd( long a, long b )
    {
    	if( a==0 ) return b;
    	return gcd( b%a, a );
    }
    
    static InputReader in = new InputReader(System.in);
    static OutputWriter out = new OutputWriter(System.out);
    
    static int i()
    {
        return in.readInt();
    }
    
    static long l()
    {
        return in.readLong();
    }
    
    static double d()
    {
        return in.readDouble();
    }
    
    static String s()
    {
        return in.readString();
    }
    
    static void Iarr( int[] array, int no )
    {
        for( int i=0 ; i<no ; i++ )
        {
            array[i] = i(); 
        }
    }
    
    static void Larr( long[] array, int no )
    {
        for( int i=0 ; i<no ; i++ )
        {
            array[i] = l(); 
        }
    }
    
    static void Darr( double[] array, int no )
    {
        for( int i=0 ; i<no ; i++ )
        {
            array[i] = d(); 
        }
    }
    
    static void Sarr( String[] array, int no )
    {
        for( int i=0 ; i<no ; i++ )
        {
            array[i] = s(); 
        }
    }
    
    private static class InputReader
    {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private SpaceCharFilter filter;
 
        public InputReader(InputStream stream)
        {
            this.stream = stream;
        }
 
        
        
        
        
        
        
        public int read()
        {
            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 readInt()
        {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            int sgn = 1;
            if (c == '-')
            {
                sgn = -1;
                c = read();
            }
            int res = 0;
            do
            {
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }
 
        public String readString()
        {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            StringBuilder res = new StringBuilder();
            do
            {
                res.appendCodePoint(c);
                c = read();
            } while (!isSpaceChar(c));
            return res.toString();
        }
        public double readDouble() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            double res = 0;
            while (!isSpaceChar(c) && c != '.') {
                if (c == 'e' || c == 'E')
                    return res * Math.pow(10, readInt());
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            }
            if (c == '.') {
                c = read();
                double m = 1;
                while (!isSpaceChar(c)) {
                    if (c == 'e' || c == 'E')
                        return res * Math.pow(10, readInt());
                    if (c < '0' || c > '9')
                        throw new InputMismatchException();
                    m /= 10;
                    res += (c - '0') * m;
                    c = read();
                }
            }
            return res * sgn;
        }
        public long readLong() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            long res = 0;
            do {
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }
        public boolean isSpaceChar(int c)
        {
            if (filter != null)
                return filter.isSpaceChar(c);
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }
 
        public String next()
        {
            return readString();
        }
 
        public interface SpaceCharFilter
        {
            public boolean isSpaceChar(int ch);
        }
    }
 
    private static class OutputWriter
    {
        private final PrintWriter writer;
 
        public OutputWriter(OutputStream outputStream)
        {
            writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
        }
 
        public OutputWriter(Writer writer)
        {
            this.writer = new PrintWriter(writer);
        }
 
        public void print(Object... objects)
        {
            for (int i = 0; i < objects.length; i++)
            {
                if (i != 0)
                    writer.print(' ');
                writer.print(objects[i]);
            }
        }
 
        public void println(Object... objects)
        {
            print(objects);
            writer.println();
        }
 
        public void close()
        {
            writer.close();
        }
 
        public void flush()
        {
            writer.flush();
        }
     }
}