#include <bits/stdc++.h>
using namespace std;
const int maxn = 100005;
const long long mod = 1e9 + 7;
char s[maxn];
int main() {
  cin.tie(0);
  ios_base::sync_with_stdio(0);
  int k;
  cin >> k >> s;
  int l = strlen(s);
  if (l <= k)
    cout << s << "\n";
  else {
    for (int i = 0; i < k; i++) cout << s[i];
    cout << "...\n";
  }
  return 0;
}
