content: package com.example;
  
  import java.io.PrintStream;
  
  public class JavaClass {
      static final PrintStream p = System.out;
  
      public static PrintStream Out = System.out;
  
      public static void main(String... args) {
          Out.println("Hello Java");
  
  //        Out.println(2/3);
  //        Out.println(2/(float)3);
  //        Out.println((float)2/3);
  //        Out.println(2f/3f);
  //        Out.println(2/3f);
  //        Out.println(2f/3);
  //
  //        demo1();
  //
  
  //        RsaClass.demo("15916015262");
  //        RsaClass.demo("15916015262");
  //        RsaClass.demo("15916015262");
  //        RsaClass.demo("15916015262");
  //        RsaClass.demo("15916015262");
  
  //        end();
  
          TestClass testClass = new TestClass();
          Out.println(testClass.num);
          testClass(testClass);
          Out.println(testClass.num);
      }
  
      public static void testClass(final TestClass testClass) {
          testClass.num = 100;
      }
  
      public static void demo1() {
          final int B = 1;
          Out.println(B);
          Out.println(B << 1);
          Out.println(B << 1 << 1);
          Out.println(B << 1 << 1 << 1);
          Out.println(B << 1 << 1 << 1 << 1);
          Out.println(B << 1 << 1 << 1 << 1 << 1);
          Out.println(B << 1 << 1 << 1 << 1 << 1 << 1);
      }
  
      public static void end() {
          Out.println("-----------------------------end----------------------------------");
      }
  
      public static class TestClass{
          public int num;
      }
  }
  