View Compilation Error

0_0_26672036_12900\Main.java:1: 错误: 需要class, interface或enum
Scanner sc = new Scanner(System.in);
^
0_0_26672036_12900\Main.java:2: 错误: 需要class, interface或enum
		while(true){
		^
0_0_26672036_12900\Main.java:4: 错误: 需要class, interface或enum
		int b = sc.nextInt();
		^
0_0_26672036_12900\Main.java:5: 错误: 需要class, interface或enum
		System.out.println(a+b);
		^
4 个错误