Think in Java第四章练习题

代码如下：

package cn.thinkinjava.yys;

public class Exercise9 {
   public static int num(int n) {
        if(n == 1){
            return 1;
        }
        if (n == 2) {
            return 1;
        }else{
            return num(n - 1) + num(n - 2);
        }
    }
    public static void main(String[] args) {
        int i = Integer.parseInt(args[0]);
        System.out.println("First"+i+"Fibonacci number(s):");
        for (int j = 0; j <= i; j++) {
            System.out.println(num(j));
        }
    }
}


运行一直出错