BigInteger Uva

import java.io.*;

import java.math.BigInteger;

import java.util.*;

public class Main {

    public static void main(String[] args)

    {

        BigInteger ans,Zero;

        Zero = BigInteger.ZERO;

        ans = BigInteger.ZERO;

        Scanner cin = new Scanner(System.in);

        while(cin.hasNextBigInteger())

        {

            BigInteger temp = cin.nextBigInteger();

            if(temp.equals(Zero)) break;

            ans = ans.add(temp);

        }

         System.out.println(ans);

    }

}

import java.io.*;

import java.math.BigInteger;

import java.util.*;

public class Main {

    public static void main(String[] args)

    {

        BigInteger a,b;

        Scanner cin = new Scanner(System.in);

        while(cin.hasNextBigInteger())

        {

            a = cin.nextBigInteger();

            b = cin.nextBigInteger();

             System.out.println(a.multiply(b));

        }

    }

}

import java.math.BigInteger;

import java.util.*;

public class Main {

    public static void main(String[] args)

    {

        BigInteger a,b,c;

        String p,q;

        Scanner cin = new Scanner(System.in);

        while(cin.hasNext())

        {

            p = cin.next();

            String s = cin.next();

            char ch = s.charAt(0);

            q = cin.next();

            System.out.println(p+" "+s+" "+q);

            a = new BigInteger(p);

            b = new BigInteger(q);

            if(ch == '+')

                c = a.add(b);

            else

                c = a.multiply(b);

            if(a.bitLength() > 31)

            {

                System.out.println("first number too big");

            }

            if(b.bitLength() > 31)

            {

                System.out.println("second number too big");

            }

            if(c.bitLength() > 31)

            {

                System.out.println("result too big");

            }

        }

    }

}