
    import java.io.BufferedReader;
    import java.io.IOException;
    import java.io.InputStreamReader;
    import java.util.StringTokenizer;


         class FastReader
        {
            BufferedReader br;
            StringTokenizer st;

            public FastReader()
            {
                br = new BufferedReader(new
                        InputStreamReader(System.in));
            }

            String next()
            {
                while (st == null || !st.hasMoreElements())
                {
                    try
                    {
                        st = new StringTokenizer(br.readLine());
                    }
                    catch (IOException  e)
                    {
                        e.printStackTrace();
                    }
                }
                return st.nextToken();
            }

            int nextInt()
            {
                return Integer.parseInt(next());
            }

            long nextLong()
            {
                return Long.parseLong(next());
            }

            double nextDouble()
            {
                return Double.parseDouble(next());
            }

            String nextLine()
            {
                String str = "";
                try
                {
                    str = br.readLine();
                }
                catch (IOException e)
                {
                    e.printStackTrace();
                }
                return str;
            }
        }

public class Main{

    public static void main(String[] args) {
        FastReader fastReader = new FastReader();
        filter( fastReader.nextInt(), fastReader.next() );

    }

    private static void filter(int reach, String s) {

        int len = s.length();
        if( len <= reach ){
            System.out.println(s);
        }else{
            System.out.print( s.substring(0, reach ) + "..." );
        }

    }
}
