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

int main()
{
	int n;
	int len = 0;
	int last = 0;
	char * vstup = (char*)malloc(sizeof(char)*10002);
	char * vystup = (char*)malloc(sizeof(char)*10001);
	char * pom = (char*)malloc(sizeof(char)*10001);

	while(1)
	{
		len = 0;
		last = 0;
		n = atoi(fgets(vstup,100,stdin));
		
		if (n == 0)
			break;

		fgets(vstup,10002,stdin);		

		int i = 0;
		int j = 0;
		int kkt; 
		
		for(i=0; vstup[i]!='\n'; i++)
		{
			if (vstup[i] != ' ') {
				if ((vstup[i] <= 'Z') && (vstup[i] >= 'A')) 
					pom[len] = vstup[i];
				else 
					pom[len] = vstup[i] - 32;		
				len++;
			}
		}

		if (n < len ) {

		for(i = 0; i < len; i++) {
			
			if (j < len) 
				last = j;
			else {
				kkt = len - 1 - last;
				j = n - kkt - 1;	
			}
			vystup[j] = pom[i];
			j = j + n;
		}
				
		vystup[len] = '\0';
		for (i = 0; i < len; i++) 
			printf("%c", vystup[i]);
		} 
		else  
			for (i = 0; i < len; i++) 
				printf("%c", pom[i]);
		printf("\n"); 
	}

	return 0;
}