import java.util.ArrayList;

public class Day08
{
    // Generates all permutations of characters in str
    public static ArrayList<String> allPermutations( String str )
    {
        ArrayList<String> result = new ArrayList<String>( );

        if( str.equals( "" ) )
            result.add( "" );
        else
        {
            for( int i = 0; i < str.length( ); i++ )
            {
                // (for each character in str)
                char thisChar = str.charAt( i );
                String smallString = str.substring( 0, i ) +
                                     str.substring( i + 1 );

                for( String s : allPermutations( smallString ) )
                    result.add( thisChar + s );
            }
        }

        return result;
    }
    
    public static void main( String [ ] args )
    {
        ArrayList<String> perms = allPermutations( "abcde" );
        System.out.println( perms.size( ) );
        System.out.println( perms );
    }
}