#include <bits/stdc++.h>
#define rep(i,n) for (int (i) = 0; (i) < (n); i++)
#define ll long long
using namespace std;
int main() {
  ll N = 0, A,B;;
  cin >> N >> A >> B;
  if(N == 1){
    cout << "Hello World";
  }
  else{
    cout << A + B;
  }
}
  
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cassert>
#include <algorithm>
#include <numeric>
#include <random>
#include <vector>
#include <array>
#include <bitset>
#include <queue>
#include <set>
#include <unordered_set>
#include <map>
#include <unordered_map>
 
using namespace std;
using uint = unsigned int;
using ll = long long;
using ull = unsigned long long;

int main() {
    string a, b ,c;
    cin >> a >> b >> c;
    if(a.back() == b.front() && b.back() == c.front()){
        cout << "YES";
    }else{
        cout << "NO";
    }
    return 0;
}