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

int main()
{
	unsigned int cislo;
	scanf("%d\n",&cislo);
	while (cislo != 0)
	{
		char buffer [10000];
		string radek = fgets(buffer,10000,stdin);
		string uradek = ""; 
		for(unsigned int i=0; i<radek.size(); i++)
			if (radek[i] != ' ' && radek[i] != '\n')
				uradek += toupper(radek[i]);
		char pismena [uradek.size()];		

		int index = 0;
		for (unsigned int i=0; i<cislo; i++)
		{
			unsigned int aktualni = i;
			while (aktualni < uradek.size())
			{
				pismena[aktualni] = uradek[index];
				index++;
				aktualni += cislo;
			}		
		}	
		for (unsigned int i=0; i<uradek.size(); i++)
		{
			printf("%c",pismena[i]);
		}
		printf("\n");
		scanf("%d\n",&cislo);
	} 	
	return 0;
}