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 Ruby (2.3.3) (judge verdict: Runtime Error)

n = STDIN.gets.chomp.to_i
posts = []
n.times do
  pts = STDIN.gets.chomp.split(/ +/).map(&:to_i)
  if pts[2] != 0
    posts << pts
  end
end
xy = []
(0..100).each do |x|
  (0..100).each do |y|
    xy << [x,y,nil]
  end
end

posts.combination(2) do |a, b|
  dh = (a[2] - b[2]).abs
  xy.delete_if do |pt|
      dha = (a[0]-pt[0]).abs + ( a[1]-pt[1]).abs
      dhb = (b[0]-pt[0]).abs + ( b[1]-pt[1]).abs
       if (dha-dhb).abs != dh
         true
       elsif pt[2] != nil && pt[2] != a[2] + dha
         true
       else
         pt[2] = a[2] + dha
         false
       end
   end
   break if xy.size == 1
end
if xy[0] == nil
  puts "nil"
else
  puts xy[0].join(" ")
end