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 <utility>
#include <vector>
#include <queue>
#include <stack>
#include <array>
#include <algorithm>
#include <numeric>
#include <limits>
#include <string>
#include <regex>
#include <cstdio>
#include <cstring>
#include <cmath>
#define INF 2000000000
#define REP(i,b,n) for(int i = (b); i < n; i++)
#define rREP(i,b,n) for(int i = n; i >= b; i--)
using namespace std;
using ll = long long;
using pi = pair<int, int>;
using vi = vector<int>;
using vvi = vector<vi>;
const int dx[] = {1, 0, -1, 0};
const int dy[] = {0, 1, 0, -1};
const string lowercase = "abcdefghijklmnopqrstuvwxyz";
const string uppercase = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
int gcd(int a, int b){return b ? gcd(b, a % b): a;}

int main()
{
    int n;
    cin >> n;
    if(n==1){
        cout << "Hello World" << endl;
    }
    else{
        int a, b;
        cin >> a >> b;
        cout << a+b << endl;
    }
    return 0;
}