[1001] A-B

package exam;
import java.util.Scanner;
public class Exam1001 {
  public static void main(String[] args){
    Scanner scanner = new Scanner(System.in);
    String AB = scanner.nextLine();
    String[] arr = AB.split(" ");
    System.out.println(Integer.valueOf(arr[0])-Integer.valueOf(arr[1]));
  }
}

Integer.valueOf 보다는 Integer.ParseInt 이용하기.