View Compilation Error

0_0_37934818_14936\Main.java:1: 错误: 需要class, interface或enum
Scanner ac =new Scanner(System.in);
^
0_0_37934818_14936\Main.java:2: 错误: 需要class, interface或enum
        int a=0,b=0;
        ^
0_0_37934818_14936\Main.java:3: 错误: 需要class, interface或enum
        if(ac.hasNextInt())
        ^
0_0_37934818_14936\Main.java:6: 错误: 需要class, interface或enum
            b=ac.nextInt();
            ^
0_0_37934818_14936\Main.java:7: 错误: 需要class, interface或enum
        }
        ^
5 个错误