从另一个包访问类

我在一个叫asdsad的文件夹里有两个文件夹

.
├── a
│   └── A.java
├── b
│   └── B.java

这是我的a.java

package asdsad.a;

public class A {
    public A() {

    }

    public int number;
}

这是我的b.java

package asdsad.b;
import asdsad.a.A;

public class B {
    public B() {

    }

    public int n = 5;

    public static void main(String[] args) {
        A a = new A();
        System.out.println(a.number);
    }
}

现在我在我的终端内的asdsad文件夹。我执行 javac a/A.java ,我没有任何错误。但当我试图 javac b/B.java ,我得到这些错误:

b/B.java:2: error: cannot find symbol
import asdsad.a.A;
               ^
  symbol:   class A
  location: package asdsad
b/B.java:12: error: cannot find symbol
        A a = new A();
        ^
  symbol:   class A
  location: class B
b/B.java:12: error: cannot find symbol
        A a = new A();
              ^
  symbol:   class A
  location: class B
3 errors