import java.util.*;

public class PrimitiveRecursive {
    public static void main(String[] args) {

        int x = -1, y = -1;
        try {
            x = Integer.parseInt(args[0]);
            y = Integer.parseInt(args[1]);
        } catch (Exception e) {
            System.out.println("Please enter valid numbers. I'll give you another chance.");
        }
        if (x < 0 && y < 0) {
            Scanner scan = new Scanner(System.in);
            System.out.println("Please enter X:");
            try {
                x = Integer.parseInt(scan.nextLine());
            } catch (Exception e) {
                System.out.println("you suck!");
                return;
            }
            System.out.println("Please enter Y:");
            try {
                y = Integer.parseInt(scan.nextLine());
            } catch (Exception e) {
                System.out.println("you suck!");
                return;
            }
        }
        System.out.println("Hang on... computing");
        int result = compute(x, y);
        System.out.println("FINALLY: " + result);

    }

    private static int compute(int x, int y) {
//      System.out.println("X: " + x + ", Y: " + y);
        if (x == 0) {
            return y+1;
        }
        if (y == 0) {
            return compute(x-1, 1);
        }
        else {
            return compute(x-1, compute(x, y-1));
        }

    }

}