import java.util.*;
class Main {
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int k = sc.nextInt();
    String s = sc.next();
    // 99の長さの "_" を作る
	String repeated = new String(new char[99]).replace("\0", "_");
	String v = s + repeated; // s の後ろに "_" を99個連結する。
	String x = v.substring(k,k+1); // 数値 k + 1番目の文字列を取り出す
	if("_".equals(x)){ // k + 1 番目が _ であれば s のまま出力
		System.out.println( s );
	}else{
        String r = s.substring(0,k); 
		System.out.println( r + "..."  );
	}
  }
}

/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz