#include <iostream>
#include <string>
#include <cctype>
#include <cstring>
using namespace std;

const int LEN = 10000;

int main()
{
	int n, i, len, ei, start;
	string str;
	char *enc = new char[LEN+1];
	//
	while(1)
	{
		cin >> n;
		if(n == 0) break;
		while(cin.get() != '\n');
		getline(cin, str);
		// odstran mezery a pocitej pocet znaku
		for(i = 0, len = 0; str[i] != 0; i++)
		{
			if(str[i] == ' ') continue;
			str[len] = toupper(str[i]);
			len++;
		}
		//
		start = 0;
		for(i = 0, ei = 0; i < len; i++, ei += n)
		{
			if(ei >= len)
			{
				start++;
				ei = start;
			}
			enc[ei] = str[i];
		}
		enc[len] = 0;
		cout << enc << '\n';
	}
	//
	delete [] enc;
	return 0;
}