#include <iostream>
#include <string>
#include <iomanip>

using namespace std;


int main(void){

	int i = 0, n, pos = 0, sp = 0, spcs = 0, size;
	string num, msg;
	char *cipher;
	
while (1){
	i = 0;
	pos = 0;
    sp = 0;
	spcs = 0;
	cin >> n;
	if (n == 0) break;
	cin.get();
	getline(cin, msg);

	size = msg.size();
	cipher = new char[size + 1];
	for (i = 0; i < size; i++){
    	cipher[i] = ' ';
		if (msg[i] == ' ') spcs++;
	}


	for (i = 0; i < size; i++){
		if (msg[i] == ' ') {
			sp++;
			continue;
		}
			
		if (size - spcs <= n){
			pos = i - sp;
		} else {
			pos = ((i - sp) * n) % (size - spcs);
		}
		cipher[pos] = toupper(msg[i]);
	}

	cipher[size - spcs] = '\0';
	cout << cipher << endl;
}
	return 0;

}