#include <bits/stdc++.h>
using namespace std;

int main() {
	// your code goes here
	string s ="hello world";
	string s1=s.substr(0,5);
	reverse(s1.begin(),s1.end());
	string s2=s.substr(6,5);
	reverse(s2.begin(),s2.end());
	s1.append(s2,0);
	reverse(s1.begin(),s1.end());
	cout<<s1;
	return 0;
}