UVA 10071 Java

import java.util.*;
import static java.lang.System.*;
 
public class main{
  public static void main(String[] args) {
    Scanner sc=new Scanner(System.in);
    while(sc.hasNextInt())
    {
    	int v = sc.nextInt();
    	int t = sc.nextInt();
    	System.out.println(v * t * 2);
    }
  }
};