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 C# (Mono 4.6.2.0) (judge verdict: Runtime Error)

using System;
using System.IO;
 
class MainClass {
    static void Main() {
        Console.SetOut(new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false });
 		string output = "";
        string line;
        while ((line = Console.ReadLine()) != null) {
            string[] tokens = line.Split(' ');
            int a = int.Parse(tokens[0]);
          	switch(a){
              case 1:
                output = "Hello World";
                break;
              case 2:
                int outputInt = int.Parse(tokens[1]) + int.Parse(tokens[2]);
                output = outputInt.ToString();
                break;
            }
            Console.WriteLine(output);
        }
 
        Console.Out.Flush();
    }
}