
#include <iostream>
#include <string>
#include <vector>
#include <array>
#include <algorithm>

namespace ABC168
{

  class B
  {
  public:
    B() = default;
    ~B() = default;


    void Run()
    {

      std::string S;
      int K= 0;
      std::cin >> K;
      std::cin >> S;

      std::string answer = S;
      if (S.length() > K)
      {
        answer = S.substr(0, K);
        answer.append("...");
      }
        

      std::cout << answer << std::endl;
    }
  };

}
int main()
{

  ABC168::B prob;
  prob.Run();

  return 0;
}



#include<bits/stdc++.h>
#define ll long long

const ll mod = 1000000007 ;

bool isInteger(double n)
{
	if(floor(n)==ceil(n))
		return true ;
	return false ;
}

using namespace std ;

int main()
{
	int k;
	cin>>k;
	string s;
	cin>>s;
	string s1="" ;
	if(s.length()<=k)
		cout<<s;
	else
	{
		for(int i=0 ;i<s.length() ;i++)
		{
			if(i<k)
				s1+=s[i];
		}
		s1+="...";
		cout<<s1;
	}

}
