#include <iostream>

int main(void) {
	char str[10001];
	char output[10001];
	char ch;
	int shift;
	int length;
	
	while(true) {
		length = 0;
		scanf("%d\n", &shift);
		if(!shift) break;
		
		while(true) {
			if((ch = getchar()) == '\n') break;
			if(ch == ' ') continue;
			if(ch >= 'a' && ch <= 'z') ch -= 32;
			str[length++] = ch;
		}
		str[length] = output[length] = 0;
		
		for(int pos = 0, start = 0, step = 0; pos < length; ++pos) {
			output[start + step * shift] = str[pos];
			if(start + ++step * shift >= length) {
				step = 0;
				++start;
			}
		}
		
		printf("%s\n", output);
	}
	
	return 0;
}