#include"bits/stdc++.h"
#include<boost/multi_array.hpp>
#include<boost/optional.hpp>
#include<boost/range/irange.hpp>
#include<boost/range/algorithm.hpp>
#include<boost/range/adaptors.hpp>
 
namespace adaptor = boost::adaptors;
 
int64_t K;
std::string S;
 
void solve()
{
    std::cin >> K >> S;
	if ((int64_t)S.size() <= K)
	{
		std::cout << S << std::endl;
		return;
	}
 
	std::cout << S.substr(0, K) << "..." << std::endl;
}
 
int main()
{
	std::cin.tie(nullptr);
	std::ios_base::sync_with_stdio(false);
	std::cout << std::fixed << std::setprecision(15);
	solve();
}