Runtime error in Fast Multiplication (MUL)

[pbs]

Why do I get runtime error in this program?
(Fast Multiplication MUL)

import java.io.*;
import java.util.*;
public class Main {
public static void main(String[] args) throws Exception {
int t;
int counter;

	BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));

       	t = Integer.parseInt(bf.readLine());

    	 for  (counter=0;counter < t; counter++) {


          		int num1 = 0 ;
		int num2 = 0 ;
                	int val = 0 ;


  			String snum = bf.readLine( );

                    StringTokenizer st = new StringTokenizer(snum);

		String snum1 = st.nextToken( );
		String snum2 = st.nextToken( );



                    num1 = Integer.parseInt(snum1);
		num2 = Integer.parseInt(snum2);

		val = num1 * num2;


               System.out.println(val);

                }



            }

        }