View Compilation Error

0_0_30222962_17692\Main.java:3: 错误: 需要class, interface或enum
public class算法 extends 算法{
       ^
0_0_30222962_17692\Main.java:5: 错误: 需要class, interface或enum
    public static void main(String[] args) {
                  ^
0_0_30222962_17692\Main.java:7: 错误: 需要class, interface或enum
                  int number2=0;
                  ^
0_0_30222962_17692\Main.java:8: 错误: 需要class, interface或enum
                  Scanner input = new Scanner(System.in);
                  ^
0_0_30222962_17692\Main.java:10: 错误: 需要class, interface或enum
            int number1 = input.nextInt();
            ^
0_0_30222962_17692\Main.java:11: 错误: 需要class, interface或enum
            int number2 = input.nextInt();
            ^
0_0_30222962_17692\Main.java:12: 错误: 需要class, interface或enum
            System.out.printf((number1 + number2));
            ^
0_0_30222962_17692\Main.java:13: 错误: 需要class, interface或enum
        }
        ^
8 个错误