#include <cstdio>
#include <string>
using namespace std;
int main(int argc, char** argv)
{
	int cipher,len,i,tile,first; string str; char c;
	scanf("%d",&cipher);
	scanf("%c",&c);
	while (cipher){
		str=""; len=0;
		scanf("%c",&c);
		while (c!='\n'){
			if (c!=' '){
				len++;
				str+=(c<'Z')?c:c-('a'-'A');
			}
			scanf("%c",&c);
		}
		tile=len/cipher;
		first=len % cipher;
		for (i=0;i<len;i++){
			printf("%c",str[(i%cipher)*tile+min(i%cipher,first)+(i/cipher)]);
		}
		printf("\n");
		scanf("%d",&cipher);
		scanf("%c",&c);
	}
	return 0;
}