package drob;

import java.util.*;

public class Constructor {

	 public static void main(String[] args) {
	        System.out.print("Строка: ");
	        Scanner s = new Scanner(System.in);
	        String str = s.nextLine();

	        int k=s.nextInt();
	        String temp;
	        String []words=str.split("[\\s\\.\\!\\,]");
	        for(int l=0;l<words.length;l++){
	            System.out.print("");
	 	            if(k<words[l].length()){
	                temp="";
	                temp+=words[l].substring(0, k-1);
	                temp+='@';
	                temp+=words[l].substring(k,words[l].length());
	 	            words[l]=temp;
	            }
	            System.out.print(" "+words[l]);
	        }
	 }
}