package jp.funnything.competition.util;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.math.BigDecimal;
import java.math.BigInteger;

import org.apache.commons.io.IOUtils;

public class QuestionReader {
    private final BufferedReader _reader;

    public QuestionReader( final File input ) {
        try {
            _reader = new BufferedReader( new FileReader( input ) );
        } catch ( final FileNotFoundException e ) {
            throw new RuntimeException( e );
        }
    }

    public void close() {
        IOUtils.closeQuietly( _reader );
    }

    public String read() {
        try {
            return _reader.readLine();
        } catch ( final IOException e ) {
            throw new RuntimeException( e );
        }
    }

    public BigDecimal[] readBigDecimals() {
        return readBigDecimals( " " );
    }

    public BigDecimal[] readBigDecimals( final String separator ) {
        final String[] tokens = readTokens( separator );

        final BigDecimal[] values = new BigDecimal[ tokens.length ];
        for ( int index = 0 ; index < tokens.length ; index++ ) {
            values[ index ] = new BigDecimal( tokens[ index ] );
        }

        return values;
    }

    public BigInteger[] readBigInts() {
        return readBigInts( " " );
    }

    public BigInteger[] readBigInts( final String separator ) {
        final String[] tokens = readTokens( separator );

        final BigInteger[] values = new BigInteger[ tokens.length ];
        for ( int index = 0 ; index < tokens.length ; index++ ) {
            values[ index ] = new BigInteger( tokens[ index ] );
        }

        return values;
    }

    public int readInt() {
        final int[] values = readInts();

        if ( values.length != 1 ) {
            throw new IllegalStateException( "Try to read single interger, but the line contains zero or multiple values" );
        }

        return values[ 0 ];
    }

    public int[] readInts() {
        return readInts( " " );
    }

    public int[] readInts( final String separator ) {
        final String[] tokens = readTokens( separator );

        final int[] values = new int[ tokens.length ];
        for ( int index = 0 ; index < tokens.length ; index++ ) {
            values[ index ] = Integer.parseInt( tokens[ index ] );
        }

        return values;
    }

    public long readLong() {
        final long[] values = readLongs();

        if ( values.length != 1 ) {
            throw new IllegalStateException( "Try to read single interger, but the line contains zero or multiple values" );
        }

        return values[ 0 ];
    }

    public long[] readLongs() {
        return readLongs( " " );
    }

    public long[] readLongs( final String separator ) {
        final String[] tokens = readTokens( separator );

        final long[] values = new long[ tokens.length ];
        for ( int index = 0 ; index < tokens.length ; index++ ) {
            values[ index ] = Long.parseLong( tokens[ index ] );
        }

        return values;
    }

    public String[] readTokens() {
        return readTokens( " " );
    }

    public String[] readTokens( final String separator ) {
        return read().split( separator );
    }
}



//Author KNIGHT0X300 

import java.util.Scanner;




public class Main {
    
    public static void main(String[] args) {
       Scanner s=new Scanner(System.in);
       int t=s.nextInt();
     long time = System.nanoTime();  
       for(int i=0;i<t;i++)
       {  int tot=0;
           int A=s.nextInt();
           int B=s.nextInt();
             int sz= (int)Math.log10(B);//digits-1
           //  System.out.println(sz);
         for(int j=B;j>A;j--)
         {  int y=j ;
           
             
         for(int k=1;k<sz+1;k++)
         {  
             int p=j%(int)Math.pow(10, k);
     //  if((p==0))
            //   continue;
         y= (int) (Math.floor(j/Math.pow(10, k))+p*(int)Math.pow(10, sz+1-k));
          
            // System.out.println(y);
//          if((p==0))//&&(p==0))
//          {  System.out.println("fahnsfjqnfjqfdjqn  "+y);}
             if((y<j)&&(y>=A)){tot++;
           System.out.println(j+" "+y);
//             if(j-y<=0)  
//                 System.out.println("wfjhdddddhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh");
//               if((p==0))//&&(p==0))
//                 System.out.println("fahnsfjqnfjqfdjqn");
             }
         
         }
         
         
         
         }
           
           
           
           
           
           
        System.out.println("Case #"+(i+1)+": "+tot);
                      
          
       }
       
 System.out.println("Finished in: " + (System.nanoTime() - time) / Math.pow(10, 6) + "ms");
    }
}
