View Compilation Error

0_0_39407222_15675\Main.java:1: 错误: 需要class, interface或enum
public int cal() {
       ^
0_0_39407222_15675\Main.java:3: 错误: 需要class, interface或enum
        while(true) {
        ^
0_0_39407222_15675\Main.java:5: 错误: 需要class, interface或enum
            int num2 = scanner.nextInt();
            ^
0_0_39407222_15675\Main.java:8: 错误: 需要class, interface或enum
            return num1+num2;
            ^
0_0_39407222_15675\Main.java:9: 错误: 需要class, interface或enum
        }
        ^
5 个错误