#include <iostream>
#include <cstdlib>
#include <cstdio>
#include <string.h>

using namespace std;

int main()
{
	char input[2000];
	char output[2000];

	for(;;)
	{
		int c;
		scanf("%d", &c);
		if (!c)
			break;

		memset(output, 0, sizeof(output));
		memset(input, 0, sizeof(input));
		int i = 0;
		char ch;
		scanf("%c", &ch);
		for (;;)
		{
			scanf("%c", &ch);
			if (ch == '\n')
				break;
			if (ch != ' ')
			{
				input[i] = ch;
				i++;
			}
		}

		int size = strlen(input);

		int j = 0;
		bool inc = true;
		int shift = 1;
		int pos = 0;
		for (i = 0; i < size; i++)
		{
			if (pos >= size && shift < c)
			{
				pos = shift;
				shift++;
			}
			output[pos] = toupper(input[i]);
			pos+=c;
		}
		printf("%s\n", output);
	}
	return 0;
}