// Working program with FastReader
import java.io.*;
import java.util.*;

public class Main
{
	static 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 static void main(String[] args)
	{
		FastReader ob=new FastReader();
		int k=ob.nextInt();
		String s=ob.next();
		if(s.length()>k){
            System.out.println(s.substring(0,k)+"...");
            return;
        }
        System.out.println(s);

	}
}
 import java.io.*; io.* java import java.util.*; util.* java public class Main
{
	static 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 static void main(String[] args)
	{
		FastReader ob=new FastReader();
		int k=ob.nextInt();
		String s=ob.next();
		if(s.length()>k){
            System.out.println(s.substring(0,k)+"...");
            return;
        }
        System.out.println(s);

	}
} Main public static void main(String[] args)
	{
		FastReader ob=new FastReader();
		int k=ob.nextInt();
		String s=ob.next();
		if(s.length()>k){
            System.out.println(s.substring(0,k)+"...");
            return;
        }
        System.out.println(s);

	} main {
		FastReader ob=new FastReader();
		int k=ob.nextInt();
		String s=ob.next();
		if(s.length()>k){
            System.out.println(s.substring(0,k)+"...");
            return;
        }
        System.out.println(s);

	} FastReader ob=new FastReader(); ob new FastReader() int k=ob.nextInt(); k ob.nextInt() ob.nextInt ob String s=ob.next(); s ob.next() ob.next ob if(s.length()>k){
            System.out.println(s.substring(0,k)+"...");
            return;
        } s.length()>k s.length() s.length s k {
            System.out.println(s.substring(0,k)+"...");
            return;
        } System.out.println(s.substring(0,k)+"...") System.out.println System.out System System.out s.substring(0,k)+"..." s.substring(0,k) s.substring s 0 k "..." return; System.out.println(s) System.out.println System.out System System.out s String[] args args static 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;
		}
	} FastReader BufferedReader br; br StringTokenizer st; st public FastReader()
		{
			br = new BufferedReader(new
					InputStreamReader(System.in));
		} FastReader {
			br = new BufferedReader(new
					InputStreamReader(System.in));
		} br = new BufferedReader(new
					InputStreamReader(System.in)) 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();
		} next {
			while (st == null || !st.hasMoreElements())
			{
				try
				{
					st = new StringTokenizer(br.readLine());
				}
				catch (IOException e)
				{
					e.printStackTrace();
				}
			}
			return st.nextToken();
		} while (st == null || !st.hasMoreElements())
			{
				try
				{
					st = new StringTokenizer(br.readLine());
				}
				catch (IOException e)
				{
					e.printStackTrace();
				}
			} st == null || !st.hasMoreElements() st == null st null !st.hasMoreElements() st.hasMoreElements() st.hasMoreElements st {
				try
				{
					st = new StringTokenizer(br.readLine());
				}
				catch (IOException e)
				{
					e.printStackTrace();
				}
			} try
				{
					st = new StringTokenizer(br.readLine());
				}
				catch (IOException e)
				{
					e.printStackTrace();
				} catch (IOException e)
				{
					e.printStackTrace();
				} IOException e {
					e.printStackTrace();
				} e.printStackTrace() e.printStackTrace e {
					st = new StringTokenizer(br.readLine());
				} st = new StringTokenizer(br.readLine()) st new StringTokenizer(br.readLine()) return st.nextToken(); st.nextToken() st.nextToken st int nextInt()
		{
			return Integer.parseInt(next());
		} nextInt {
			return Integer.parseInt(next());
		} return Integer.parseInt(next()); Integer.parseInt(next()) Integer.parseInt Integer next() next long nextLong()
		{
			return Long.parseLong(next());
		} nextLong {
			return Long.parseLong(next());
		} return Long.parseLong(next()); Long.parseLong(next()) Long.parseLong Long next() next double nextDouble()
		{
			return Double.parseDouble(next());
		} nextDouble {
			return Double.parseDouble(next());
		} return Double.parseDouble(next()); Double.parseDouble(next()) Double.parseDouble Double next() next String nextLine()
		{
			String str = "";
			try
			{
				str = br.readLine();
			}
			catch (IOException e)
			{
				e.printStackTrace();
			}
			return str;
		} nextLine {
			String str = "";
			try
			{
				str = br.readLine();
			}
			catch (IOException e)
			{
				e.printStackTrace();
			}
			return str;
		} String str = ""; str "" try
			{
				str = br.readLine();
			}
			catch (IOException e)
			{
				e.printStackTrace();
			} catch (IOException e)
			{
				e.printStackTrace();
			} IOException e {
				e.printStackTrace();
			} e.printStackTrace() e.printStackTrace e {
				str = br.readLine();
			} str = br.readLine() str br.readLine() br.readLine br return str; str public class Main
{
	static 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 static void main(String[] args)
	{
		FastReader ob=new FastReader();
		int k=ob.nextInt();
		String s=ob.next();
		if(s.length()>k){
            System.out.println(s.substring(0,k)+"...");
            return;
        }
        System.out.println(s);

	}
} public class Main
{
	static 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 static void main(String[] args)
	{
		FastReader ob=new FastReader();
		int k=ob.nextInt();
		String s=ob.next();
		if(s.length()>k){
            System.out.println(s.substring(0,k)+"...");
            return;
        }
        System.out.println(s);

	}
} Main
// Working program with FastReader
import java.io.*;
import java.util.*;

public class Main
{
	static 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 static void main(String[] args)
	{
		FastReader ob=new FastReader();
		int k=ob.nextInt();
		String s=ob.next();
		if(s.length()>k){
            System.out.println(s.substring(0,k)+"...");
            return;
        }
        System.out.println(s);

	}
}

