Main.java:1: 错误: 需要class, interface或enum
Scanner scanner = new Scanner(System.in);
^
Main.java:2: 错误: 需要class, interface或enum
int a = scanner.nextInt();
^
Main.java:3: 错误: 需要class, interface或enum
int b = scanner.nextInt();
^
Main.java:4: 错误: 需要class, interface或enum
System.out.println(a b);
^
4 个错误