Main.java:2: error: '{' expected
public class pra
                ^
Main.java:3: error: class, interface, enum, or record expected
    public static void main(String[] args){
                  ^
Main.java:5: error: class, interface, enum, or record expected
        System.out.println("请输入两个数");
        ^
Main.java:6: error: class, interface, enum, or record expected
        int a=sc.nextInt();
        ^
Main.java:7: error: class, interface, enum, or record expected
        int b=sc.nextInt();
        ^
Main.java:8: error: class, interface, enum, or record expected
        System.out.println("输出结果为"+a+b);
        ^
Main.java:9: error: class, interface, enum, or record expected
    }
    ^
7 errors