Problem:
﻿Score: 100 points

Problem Statement

In 2020, AtCoder Inc. with an annual sales of more than one billion yen (the currency of Japan) has started a business in programming education.

One day, there was an exam where a one-year-old child must write a program that prints Hello World, and a two-year-old child must write a program that receives integers A, B and prints A+B.

Takahashi, who is taking this exam, suddenly forgets his age.

He decides to write a program that first receives his age N (1 or 2) as input, then prints Hello World if N=1, and additionally receives integers A, B and prints A+B if N=2.

Write this program for him.

Constraints

N is 1 or 2.

A is an integer between 1 and 9 (inclusive).

B is an integer between 1 and 9 (inclusive).

Input

Input is given from Standard Input in one of the following formats:

1

2
A
B

Output

If N=1, print Hello World; if N=2, print A+B.

Sample Input 1

1

Sample Output 1

Hello World

As N=1, Takahashi is one year old. Thus, we should print Hello World.

Sample Input 2

2
3
5

Sample Output 2

8

As N=2, Takahashi is two years old. Thus, we should print A+B, which is 8 since A=3 and B=5.

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.stream.Stream;

public class Main {
    private static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    private static PrintWriter pw = new PrintWriter(System.out);
    public static void main(String[] args) throws IOException {
        int n = nextInt();
        if(n == 1){
            println("Hello World");
        }else{
            int a = nextInt();
            int b = nextInt();
            println(a + b);
        }
        // 解答ここから
//        int N = nextInt();
//        int[] X = arrayOfInt();
//        int[] x = X.clone();
//        Arrays.sort(x);
//        // 中央値の境界を取る
//        int floor = N/2 - 1;
//        int border = x[floor];
//
//        int a = x[floor + 1];
//        int b = x[floor];
//        for(int i = 0;i < N;i++){
//            if(X[i] <= border){
//                println(a);
//            }else{
//                println(b);
//            }
//        }

        //解答ここまで
        pw.flush();
        return;
    }
    // 入力受け取り
    static String next() throws IOException {return br.readLine();}
    static int nextInt() throws IOException{return getInt(br.readLine());}
    static long nextLong() throws IOException{return getLong(br.readLine());}
    static String[] arrayOfString() throws IOException{return br.readLine().split(" ");}
    static int[] arrayOfInt() throws IOException{return toIntArray(arrayOfString());}
    // 変換
    static long getLong(String val) {return Long.parseLong(val);}
    static int getInt(String val) {return Integer.parseInt(val);}
    static int[] toIntArray(String[] array) {return Stream.of(array.clone()).mapToInt(Integer::parseInt).toArray();}
    static String joinToString(String[] array) {
        StringBuilder sb = new StringBuilder();
        for(int i = 0;i < array.length;i++) sb.append(array[i]);
        return sb.toString();
    }

    // 出力
    static void println(Object val){pw.println(val);}
}