#include <cstring>
#include <cstdlib>
#include <cstdio>
#include <iostream>

using namespace std;

char toupper(const char c)
{
  if(c > 96)
    {
      return(c - 32);
    }
  return(c);
}

int main(void)
{
  while(1)
    {
      int n, cnt=0;
      char orig[10000];
      char enct[10000];
      char c;
		
      scanf("%d", &n);
      getchar();
		
      //printf("n is: %d\n", n);
		
      if(n == 0)
	{
	  break;
	}
		
      while( ((c = getchar()) != '\n') )
	{
		
	  if(c == ' ')
	    continue;
	  orig[cnt] = toupper(c);
	  cnt++;
	}
		
      //printf("cnt is: %d\n", cnt);
      if(cnt < n)
	{
	  cout << orig << endl;
	}
      else
	{
	  int pos_old = 0 - n;
	  int round = 0;
	  for(int i = 0; i < cnt; i++)
	    {
	      int pos = (pos_old + n) % cnt;
	      if(pos < pos_old)
		{
		  round++;
		  pos_old = 0 - n + round;
		  i--;
		  continue;
		}
	      pos_old = pos;
	      /*printf("i %d pos %d cnt %d\n", i, pos, cnt);*/
	      //printf("pos is: %d\n", pos);

	      enct[pos] = orig[i];
	      //orig[i] = '\0';
	    }
	  cout << enct << endl;
	}
		
      //printf("%s\n", enct);
		
		
      for(int i = 0; i < cnt; i++)
	{
	  enct[i] = 0;
	  orig[i] = 0;
	}
		
    }
  return(0);
}