// GoBack.java
// CS101 lecture on recursion
// Demonstrates pending operations after recursive call

public class GoBack {
  
    public static void main(String[] args) {
        if (args.length != 1) {
            System.out.println("Usage: java GoBack <int>");
            return;
        }
        int n = Integer.parseInt(args[0]);
        goBack(n);
    }
  
    public static void goBack(int n) {
        if (n == 0) {
            System.out.println("Stop");
        } else {
            System.out.println("Go " + n);
            goBack(n-1);
            System.out.println("Back " + n);
        }
    }
}