#include <stdio.h>
#include <string.h>
#include <string.h>
#include <ctype.h>
using namespace std;

#define DEBUG 0
#define III if(DEBUG)
#define LEN 11000

int main() {
  int a,b, N;
  char line[LEN], line2[LEN], line3[LEN],  *end;
  //int inty[];
  scanf("%d\n", &N);
  while(N) {
    fgets(line, LEN-1, stdin);
    a=b=0;
    while( line[a] ){
	   if ( ! isspace(line[a]) ) {
	     line2[b]=toupper( line[a] );
		 b++;
	   }
	   a++;
	} //line2 is CLEAN!
	line2[b]=0;
	line3[b]=0;
	end =line3+b;
	
	III printf("Line2 %d: %s\n", __LINE__, line2);
	III printf("Line3 bef %d: %s\n", __LINE__, line3);
	
	if(N>=b)
	  printf("%s\n", line2);
	else {
	  char *base  =line3;
	  char *base2;
	  char *baseO =line2;
	  while( baseO -line2 <b ) {
	    base2 =base;
  	    while (base2 <end) {
	      *base2 =*baseO;
		  base2 +=N;
		  baseO ++;
	    }
	    base ++;
	  }
	  //line3[b]=0;  
	  printf("%s\n", line3);
	}
	
	
	//next case
    scanf("%d\n", &N);
  }
  return 0;
}