#include <cstdlib>
#include <cstdio>
#include <cmath>
#include <iostream>

using namespace std;

int main(){
	while(1){
		//nacitani
		int figure;
		scanf("%d\n", &figure);
		if(figure==0)
			break;	
		
		int pocet=0;
		int max=5;
		int i=0;
		char znak;
		char* pole;
		pole = (char*) malloc ( max * (sizeof(char)));
		while(1){
			scanf("%c", &znak);
			if(znak=='\n'){
				//cout<<"ahoj"<<endl;
				pocet=i;
				break;
			}
			else{
				if((int)znak==32){
				}
				else if((int)znak>=97){
					znak=(int)znak-32;
					pole[i]=znak;
					i++;
				}
				else{
					pole[i]=znak;
					i++;
				}
				if(i==max){
					max*=2;
					pole = (char*) realloc (pole, max * sizeof(char));	
				}
			}
		}
		//vypis
		/*
		for(int j=0;j<pocet;j++){
			printf("%c",pole[j]);
		}
		printf("\n");
		*/
		//sifrovani
		char* pole_new;
		pole_new = (char*) malloc ( pocet * (sizeof(char)));
		for(int k=0,l=0, p=0;k<pocet;k++,l+=figure){
			if(l>=pocet){
				//printf("doslo na konec..%d,%d\n",l,p);
				p++;
				l=p;
				//printf("doslo na konec..zacatek..%d,%d\n",l,p);
			}
			//printf("pole_new[%d]=... pole[%d]=%c\n",l,k,pole[k]);
			pole_new[l]=pole[k];
		}
		
		
		
		//vypis
		
		for(int j=0;j<pocet;j++){
			printf("%c",pole_new[j]);
		}
		//printf("\n");
		cout<<endl;
		
		//uvolneni
		free(pole);
		free(pole_new);
	}
	return 0;
}