#include <iostream>
#include <string>

using namespace std;

void
remwhite(string& in, string& out){
    for(unsigned int i = 0; i < in.size(); ++i){
        if(in[i] != ' '){
        	if('a' <= in[i] && in[i] <= 'z'){
            	out.push_back(in[i] + 'A' - 'a');
            }
            else{
            	out.push_back(in[i]);
            }
        }
	}
}

int
main(){
    unsigned int n;
    string s;
    
    cin >> n;
    cin.ignore();
    
    while(n != 0){
    	string s2;
       	getline(cin, s);
       	remwhite(s, s2);
       	
       	string s3(s2.size(), ' ');
       	
       	unsigned int begin = 0;
       	unsigned int j = 0;
       	for(unsigned int i = 0; j < s2.size(); i+=n, ++j){
       		if(i >= s2.size()){
       			i = ++begin;
       		}
       		s3[i] = s2[j];
       	}
       	
       	cout << s3 << endl;    
    
       	cin >> n;
       	cin.ignore();
    }
    
    return 0;
}