#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i, n) for(ll i = 0; i < (ll)(n); i++)
#define rep2(i, a, n) for(ll i = a; i < (ll)(n); i++)
#define memi cout << endl
#define kono(n) cout << fixed << setprecision(n)
#define all(c) (c).begin(), (c).end()
#define pb push_back
#define hina cout << ' '
#define in(n) cin >> n
#define in2(n, m) cin >> n >> m
#define in3(n, m, l) cin >> n >> m >> l
#define out(n) cout << n
const ll mei = (ll)1e9 + 7;

int main(){
  ll k, a;
  string s;
  in2(k, s);
  if(s.size() <= k)
    out(s);
  else{
    rep(i, k)
      out(s[i]);
    rep(i, 3)
      out('.');
  }
  memi;
}
#include<iostream>
#include<bits/stdc++.h>
#include<climits>

#define forn(x,n,s) for(int i = x; i < n; i += s )
#define forr(x,n,s) for(int i = x; i>=n; i -= s)

using namespace std;

void go(){
  ios_base::sync_with_stdio(0);
  cin.tie(0);

  #ifndef ONLINE_JUDGE
       freopen("input.txt","r",stdin);
       freopen("output.txt","w",stdout);
  #endif
} 
long long int mod = 1e9+7;

int main(){
    go(); 

    // code here
    int k;cin>>k; 
    string s;cin>>s;
    if(s.length() <= k) cout<<s;
    else cout<<s.substr(0,k)+"...";
}




