#include<iostream>
#include<string>
#include<algorithm>
#include<vector>
#include<set>
#include<iomanip>
#define rep(i, a, n) for(int i = a; i < n; i++)
using namespace std;
int main(){
  int a, b, c;
  cin >> a;
  if(a == 1){
    cout << "Hello World\n";
    return 0;
  }
  if(a == 2){
    cin >> b >> c;
    cout << b + c << "\n";
    return 0;
  }
}
  
#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cmath>
#include <string>
#include <cctype>

using namespace std;

int main() {

	string st;
	int stlen;

	while (cin >> st) {
		stlen = st.size();
		for (int i = stlen - 1; i >= 0; i--) {
			cout << st[i];
		}
		putchar('\n');
	}
	
	return 0;
}