#include <bits/stdc++.h>
#define booga cout << "booga" << endl
#define ll long long int
/* run this program using the console pauser or add your own getch, system("pause") or input loop */
using namespace std;

int main(){
	ios::sync_with_stdio(false);
	cin.tie(0);
	int n,a,b;
	cin >> n >> a >> b;
	if(n == 1){
		cout << "Hello World ";
	}
	else{
		cout << a+b;
	}
	return 0;
}




#include<iostream>
#include<cstdio>
#include<cmath>
using namespace std;

int main()
{
	double ax, ay, bx, by;
	cin >> ax >> ay >> bx >> by;
	printf("%.6f\n",sqrt(pow(bx-ax,2)+pow(by-ay,2)));
    return 0;
}