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: Accepted)

using System;
class Program
{
  static void Main(string[] args)
  {
    if(Read()==1){
      Write("Hello World");
    }else{
      Write(Read()+Read());
    }
  }

  static void Write(string s) { Console.WriteLine(s); return; }
  static void Write(long n) { Console.WriteLine(n.ToString()); return; }
  static string ReadStr() { return Console.ReadLine(); }
  static string[] ReadStrs() { return Console.ReadLine().Split(' '); }
  static long Read() { return long.Parse(Console.ReadLine()); }
  static long[] Read(long n) {
    long[] p = new long[n];
    string[] t = Console.ReadLine().Split(' ');
    for(long i = 0; i < n; i++) { p[i] = long.Parse(t[i]); }
    return p;
  }
  static long abs(long n) { return (n > 0) ? n : -n; }
  static long gcd(params long[] n) { long p = n[0]; for (long i = 1; i < n.Length; i++) { p = gcd(p, n[i]); } return p; }
  static long gcd(long a, long b) { return (a==0)?b:gcd(b % a, a); }
  static long lcm(params long[] n) { long p = n[0]; for (long i = 1; i < n.Length; i++) { p = lcm(p, n[i]); } return p; }
  static long lcm(long a, long b) { return a * b / gcd(a, b); }
  static long max(params long[] n) { long p = n[0]; for (long i = 1; i < n.Length; i++) { p = (p>n[i])?p:n[i]; } return p; }
  static long min(params long[] n) { long p = n[0]; for (long i = 1; i < n.Length; i++) { p = (p<n[i])?p:n[i]; } return p; }
  static void YN(bool t) { Console.WriteLine(t ? "YES" : "NO"); }
  static void Yn(bool t) { Console.WriteLine(t ? "Yes" : "No"); }
  static void yn(bool t) { Console.WriteLine(t ? "yes" : "no"); }
  static string clip(string s, int start, int count) {
    if (start + count < s.Length) { s = s.Remove(start + count); }
    if (start > 0) { s = s.Remove(0, start); }
    return s;
  }
}