UVa - 389 Basically Speaking

//java solution
import java.util.*;
import java.util.regex.*;
import java.io.*;
import java.awt.geom.*;
import java.math.*;
import java.text.*;

class Main
{


    public static void main (String args[])  // entry point from OS
    {
        Main myWork = new Main();  // create a dynamic instance
        myWork.Begin();            // the true entry point
    }

    void Begin()
    {

String s,cs;
int b,t;
BigInteger a;
Scanner sc=new Scanner(new BufferedReader(new InputStreamReader(System.in)));
PrintWriter pr=new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));
try
 {
sc=new Scanner(new BufferedReader(new FileReader("F:\\INPUT.TXT")));
}
 catch(Exception e)
 {
     System.exit(0);
 }

   //default delimiter : "\\s+"
            // that means spaces , tabs , newlines(form feeds , carriage returns)
            // are skipped
            while(sc.hasNext())
    {
    s=sc.next();
    b=sc.nextInt();
    t=sc.nextInt();
    a=new BigInteger(s,b);
    cs=a.toString(t);
        if(cs.length()>7)
            pr.printf("%7s%n","ERROR");
        else
        {
            cs=cs.toUpperCase();
            pr.printf("%7s%n",cs);
        }
        }
    pr.close();
    sc.close();
    }
}