#include "stdio.h"
#include "memory.h"

#define MAX 100001

int main()
{
  int enc,len;

  while(true)
	{	
		scanf("%d", &enc);
		
		if (enc==0)	
			return 0;
		
		getchar();

		char pole[MAX];
		memset(pole, 0, MAX);

		int k=0; char c = -1;
		while (c!='\n')
		{
			scanf("%c", &c);
			if (c != ' ' && c!='\n')
			{
				pole[k]=(c <= 'z' && c>='a')?(c-('a'-'A')):c;
				k++;
			}
		}

		len = strlen(pole);  

		int i=0, pos=0, j=0, id=i;
		char vystup[len+1];
		memset(vystup, 0, len+1);

   		while(i<len)
		  {
		    int k = ((i*enc)%len);
		bool done=false;
		while(!done)
		  {
		    if (vystup[k] == 0) break;
		   
		    k++;
		    if (k>=len)
		      k=0;
		  }
		   vystup[k] = pole[i];
		   i++;
	          }
		printf("%s\n", vystup);
	}

  return 0;
}