[인터페이스함수]다시한번 해보자

import java.io.IOException;
import java.nio.charset.Charset;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.*;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.stream.Stream;

public class z1 {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String z = sc.next();
        calcu c = new calcu();



        System.out.println(          c.cc(3,5,z,(a,b)->{
            if(z.equals("+")){
                return a+b;
            } else if(z.equals("-")){
                return a-b;
            } else{
                return 0;
            }

        })   );

    }
}


class calcu{
    public int cc(int a, int b, String z, cal c){
        return c.operate(a,b);
    }

}

interface cal{

    public int operate(int a, int b);
}