import java.io.*;
import java.util.*;

public class Bolador {
	
	private String[] nomeArq =
	{ "../easy.txt", "../medium.txt", "../hard.txt", "../super.txt" };
	
    public int[][] mandaProbl ( int nivel ) {
    	// escolhe problema
    	int p[][] = new int[9][9];
    	Random r = new Random ();
    	try {
    		File f = new File ( nomeArq[nivel] );
    		long nProblems = f.length() / 82;
    		int chooseFrom;
    		if ( nProblems > Integer.MAX_VALUE )
    			chooseFrom = Integer.MAX_VALUE;
    		else
    			chooseFrom = (int) nProblems;
    		BufferedReader in = new
    		BufferedReader ( new 
    				InputStreamReader ( new
    						FileInputStream ( f )));
    		in.skip ( 82*r.nextInt ( chooseFrom ) );
    		String s = in.readLine ();
    		for ( int i = 0; i < 9; i++ ) {
    			for ( int j = 0; j < 9; j++ ) {
    				char c = s.charAt(i*9+j);
    				p[i][j] = Character.digit( c, 10 );
    				if ( p[i][j] < 0 )
    					// digito invalido
    					p[i][j] = 0;
    			}
    		}
    	}
    	catch ( Exception e ) {
    		System.out.println( e );
    	}
    	return p;
    }
}