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++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <iostream>
#include <string>
#include <vector>
#include <map>
#include <cmath>
#include <algorithm>
#include <functional>
#include <stack>
#include <numeric>
typedef long long ll;
using namespace std;
const int MOD = (int)1e9 + 7;
const ll INF = (ll)1e18 + 7;
#define int long long
#define vint vector<int>
#define pint pair<int,int>
#define pb(a) push_back(a)
#define all(v) v.begin(),v.end()
#define dbg(x) cerr << #x << " = " << (x) << endl
#define yn(b) cout << ((b) ? "Yes" : "No") << endl
#define YN(b) cout << ((b) ? "YES" : "NO") << endl

int dx[4] = {0, 1, 0, -1};
int dy[4] = {1, 0, -1, 0};

signed main()
{
	cin.tie(0);
	ios::sync_with_stdio(false);

	int N;
	cin >> N;

	if(N==1){
		cout << "Hello World" << endl;
	}else{
		int a, b;
		cin >> a >> b;
		cout << a + b << endl;
	}

	return 0;
}