#include<iostream>
#include<string>

int main() {
	int K;
	std::string S;
	std::cin >> K >> S;
	if (S.size() <= K) std::cout << S << std::endl;
	else {
		std::string answer = S.substr(0, K);
		answer += "...";
		std::cout << answer << std::endl;
	}
	return 0;
}
#include <bits/stdc++.h>
#include<algorithm>
#include<cstring>
#include<cmath>
#include<cstdlib>
#include<string.h>
using namespace std;
#define pb push_back
#define all(v) v. begin(),v. end()
#define  rep(i,n,v) for(i=n;i<v;i++)
#define per(i,n,v) for(i=n;i>v;i--)
#define ff first 
#define ss second 
#define pp pair<ll,ll>
#define eps 1e-6
#define ll  long long
#define endl '\n'
void solve()
{
  ll n, a,m=0,b=1, k=0, i, j,l=2e9+7;
  string s, r, y;
  cin>>n>>s;
 rep(i,0,s.length())
 {
   if(i==n) break;
   cout<<s[i];
 }
 if(i!=s. length())
 cout<<"...";
}
int main()
{
 ios_base::sync_with_stdio(false);
  cin. tie(0);cout. tie(0);
    ll t=1;
  // cin>>t;
    while(t--)
    {
      solve();
    }
    return 0;
}