# [15552/JAVA] 빠른 A+B

import java.io.*;
import java.util.StringTokenizer;

public class Main {
    public static void main(String[] args) throws IOException {
            BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
            BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
            
            int T = Integer.parseInt(br.readLine());
            
            StringTokenizer st;
            
            for (int i = 0; i < T; i++) {
                st = new StringTokenizer(br.readLine(), " ");
                
                int A = Integer.parseInt(st.nextToken());
                int B = Integer.parseInt(st.nextToken());
                
                bw.write(A+B + "\n");

            }
            bw.flush();
            bw.close();
            br.close();
    }
}

 

 

import java.util.*;
import java.io.*;

public class Main {
public static void main(String[] args)throws IOException{

BufferdReader br = new BufferdReader(new InputStreamReader(System.in));
BufferedWriter bw = new BufferdWriter(new OutputStreamWriter(System.out));

int n= Integer.parseInt(br.readLine());

StringTokenizer st; //한줄로 받도록 조건 설정됨, split 처럼 사용가능

for (int i=0; i<n; i++)
{
st = new StirngTokenizer(br.readLine(), " ");

int a= Integer.parseInt(st.nextToken());
int b= Integer.parseInt(st.nextToken());
bw.write(a+b + "\n"); //자동개행 기능이 없기때문에 개행 필수 
}
bw.flush(); //데이터 모두 화면에 출력
bw.close(); //
br.close();

}
}

아니 진짜 못해먹갯네 Reader 이랑 Writer 다시 배우고 오겠읍니다

 

#R, W 개념 정리된 블로그 

https://velog.io/@kyukim/%EC%9E%90%EB%B0%94-%EB%B0%B1%EC%A4%80-15552%EB%B2%88-BufferedReader-BufferedWriter