// Let's use the command line to add some numbers.
public class Add
{
  public static void main(String [] args)
  {
    // For each number in the command line, let's add it to the total.
    int sum = 0;
    for (int i = 0; i < args.length; ++i)
    {
      try
      {
        sum += Integer.parseInt(args[i]);
      }
      catch(NumberFormatException e)
      {
        continue;
      }
    }
    System.out.printf("The sum of the integers is %d\n", sum);
  }
}

// When I first typed the program, I was in a hurry and I typed
// args[0] instead of args[i], so the program said the sum of 7,2,6,-3
// 28 because it was adding 7 four times.