import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Scanner;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TripleDots solver = new TripleDots();
        solver.solve(1, in, out);
        out.close();
    }

    static class TripleDots {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            int k = in.nextInt();
            String s = in.next();

            if (s.length() <= k) {
                out.append(s);
                return;
            }

            out.append(s.substring(0, k) + "...");

        }

    }
}
 import java.io.OutputStream; OutputStream java.io import java.io.IOException; IOException java.io import java.io.InputStream; InputStream java.io import java.io.PrintWriter; PrintWriter java.io import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TripleDots solver = new TripleDots();
        solver.solve(1, in, out);
        out.close();
    }

    static class TripleDots {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            int k = in.nextInt();
            String s = in.next();

            if (s.length() <= k) {
                out.append(s);
                return;
            }

            out.append(s.substring(0, k) + "...");

        }

    }
} Main public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TripleDots solver = new TripleDots();
        solver.solve(1, in, out);
        out.close();
    } main {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TripleDots solver = new TripleDots();
        solver.solve(1, in, out);
        out.close();
    } InputStream inputStream = System.in; inputStream System.in System System.in OutputStream outputStream = System.out; outputStream System.out System System.out Scanner in = new Scanner(inputStream); in new Scanner(inputStream) PrintWriter out = new PrintWriter(outputStream); out new PrintWriter(outputStream) TripleDots solver = new TripleDots(); solver new TripleDots() solver.solve(1, in, out) solver.solve solver 1 in out out.close() out.close out String[] args args static class TripleDots {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            int k = in.nextInt();
            String s = in.next();

            if (s.length() <= k) {
                out.append(s);
                return;
            }

            out.append(s.substring(0, k) + "...");

        }

    } TripleDots public void solve(int testNumber, Scanner in, PrintWriter out) {
            int k = in.nextInt();
            String s = in.next();

            if (s.length() <= k) {
                out.append(s);
                return;
            }

            out.append(s.substring(0, k) + "...");

        } solve {
            int k = in.nextInt();
            String s = in.next();

            if (s.length() <= k) {
                out.append(s);
                return;
            }

            out.append(s.substring(0, k) + "...");

        } int k = in.nextInt(); k in.nextInt() in.nextInt in String s = in.next(); s in.next() in.next in if (s.length() <= k) {
                out.append(s);
                return;
            } s.length() <= k s.length() s.length s k {
                out.append(s);
                return;
            } out.append(s) out.append out s return; out.append(s.substring(0, k) + "...") out.append out s.substring(0, k) + "..." s.substring(0, k) s.substring s 0 k "..." int testNumber testNumber Scanner in in PrintWriter out out public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TripleDots solver = new TripleDots();
        solver.solve(1, in, out);
        out.close();
    }

    static class TripleDots {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            int k = in.nextInt();
            String s = in.next();

            if (s.length() <= k) {
                out.append(s);
                return;
            }

            out.append(s.substring(0, k) + "...");

        }

    }
} public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TripleDots solver = new TripleDots();
        solver.solve(1, in, out);
        out.close();
    }

    static class TripleDots {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            int k = in.nextInt();
            String s = in.next();

            if (s.length() <= k) {
                out.append(s);
                return;
            }

            out.append(s.substring(0, k) + "...");

        }

    }
} Main
import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Scanner;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TripleDots solver = new TripleDots();
        solver.solve(1, in, out);
        out.close();
    }

    static class TripleDots {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            int k = in.nextInt();
            String s = in.next();

            if (s.length() <= k) {
                out.append(s);
                return;
            }

            out.append(s.substring(0, k) + "...");

        }

    }
}

