#include<stdio.h>
#include<stdlib.h>
#include<ctype.h>


int main(int argc, char * argv[]){
	char buffer[10000];
	char final[10000];
	char * checker;
	int countnumber = 0, skip;
	int index = 0;
	int f_start=0;
	
	scanf("%d ", &skip);
	while(skip != 0){
		index = f_start = countnumber = 0;
		fgets(buffer,10000,stdin);
		checker = buffer;
	
		while(*checker != '\0'){
			if((*checker >= 'a' && *checker <='z') || (*checker >= 'A' && *checker <= 'Z')){
				countnumber++;
			}
			checker++;
		}
		
		checker = buffer;
		
		while(*checker != '\0'){
			if((*checker >= 'a' && *checker <='z') || (*checker >= 'A' && *checker <= 'Z')){
				if(*checker >= 'a' && *checker <= 'z'){
					*checker -='a';
					*checker +='A';
				}
				
				final[index] = *checker;
				index += skip;
				
				if(index >= countnumber){
					index = ++f_start;
					}
			}
			
			
			checker++;
		}
		
		
		final[countnumber] = '\0';
		printf("%s\n",final);
		scanf("%d ", &skip);	
	}

return(0);
		
}