#include<iostream>

using namespace std;

const int MAX = 10000;

int main(){
  int N;
  cin >> N;
  char c;
  char message[MAX];
  for (int i=0;i<MAX;i++)
    message[i] = 32;
  int index = -1;
  int pocet = 0;
  
  while(N > 0){
    cin.ignore();
    cin.getline(message,MAX);
    pocet = 0;
    for (int i = 0;i<MAX;i++){
      pocet++;
      if (message[i+1] ==  '\0')
	break;
      
      
      
    }
    //cout << N << endl;
    //cout << pocet << endl;
    char *text = new char[pocet];
    int t = pocet;
    for (int i =0; i<t; i++){
      
      if ((message[i] > 64) && (message[i] < 123)){
	text[++index] = message[i];
        if (text[index] > 96)
	  text[index] -= 32;
      }
      else{
	/*cout << */pocet--;
      }
      
      
    }
    
    /*for (int i = 0; i< pocet;i++)
      cout << text[i];*/
    
    int odecist = N - (pocet-N);
    if (odecist <=0)
      odecist = 0;
    char *text2 = new char[pocet-odecist]; //text
   
    
    char *sifra = new char[pocet];
    
    for (int i = 0;i<(pocet-odecist);i++)
      text2[i] = text[i];
    index = -1;
    //cout << pocet << endl;
    for (int i = 0;i<(pocet-odecist);i+= (((pocet-odecist)/N)+1)){
      sifra[++index] = text2[i];
    }
    
    if (odecist > 0){
      char *text3 = new char[odecist];//zbytek
      for (int i = (pocet-odecist);i<pocet;i++)
        text3[i-(pocet-odecist)] = text[i];
      int b = index;
      for (int i = ++b;i< b+odecist;i++)
	sifra[++index] = text3[i-b];
	
      
      
    }
    
    
    for(int i = 1;i<((pocet-odecist)/N)+1;i++){
     
      for(int j = i;j<(pocet-odecist); j+=(((pocet-odecist))/N)+1){
        sifra[++index] = text2[j];
       
      
      }
    }
    
    for(int i = 0;i < pocet;i++)
      cout << sifra[i];
    
    index = -1;
    cin >> N;
    pocet = 0;
  }
      
	
	
  
  
  
 



  return 0;
}