#include <stdio.h>
#include <list>
#include <ctype.h>

int N;

std::list<char> str;
std::list<char> enc;
std::list<char> tmp;


void encrypt()
{
	std::list<char>::iterator iter;
	
	while (!str.empty())
	{
		int mam = str.size();
	
		enc.push_back(str.front());
		
		str.pop_front();
		mam--;
				
		int x = 0;
		tmp.clear();
		int u;
		
		while (mam > 0)
		{
			x = (x + mam / N) % mam;
		
			iter = str.begin();			
			for (u = 0; u < x; u++)
			{
				iter++;
			}
			
			enc.push_back(*iter);	
					
			str.erase(iter);			
			mam--;	
			
		}
		break;
		while (!tmp.empty())
		{
			str.push_back(tmp.front());
			tmp.pop_front();
		}
	}	
	//unsigned i;

	for (iter = enc.begin(); iter != enc.end(); iter++)
	{
		printf("%c", *iter);
	}
	printf("\n");
	enc.clear();
	str.clear();	
}


int main()
{
	char c;
	while (1)
	{	
		scanf("%d", &N);
		getchar();
		if (N == 0) break;
		
		while ((c = getchar()) != '\n')
		{
			if (c == ' ') continue;
			str.push_back(toupper(c));					
		}
			
		encrypt();
	}
	
	
	return 0;
}