#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cctype>

bool solve() {

	int N;
	scanf("%d\n", &N);
	if (N == 0) return false;
	
	char buffer[20000];
	char text[10001];
	memset(buffer, 0, sizeof(buffer));
	memset(text, 0, sizeof(text));
	
	fgets(buffer, 15000, stdin);
	char* c = text;
	char* b = buffer;
	while(*b) {
		if (*b != ' ' && isalpha(*b)) {
			*c = toupper(*b);
			b++;
			c++;
		}
		else b++;
	}

	int max = strlen(text);

	char en[10001];
	memset(en, 0, sizeof(en));
	int p = 0;
	c = text;
	while (*c) {
		//printf("Store %c on %d\n", *c, p);
		en[p] = *c;
		int i = 0;
		while (i < N) {
			p++;
			//printf("%d", p);
			if (p >= max) break;
			//if (!en[p]) i++;
			i++;
		}
		if (i < N) {
			p = 0;
			while (en[p])
				p++;
		}
		c++;
	}

	printf("%s\n", en);

	return true;
}

int main(int, char**) {
	while (solve());
	return EXIT_SUCCESS;
}