int main(null){
	char pole[10000];
	char poleVychozi[10000];
	int N;
	char c;
	int counter;
	while(1){
		scanf("%d",&N);
		if ( !N ) break;
		counter = 0;
		
		//nacist vstup;
		getchar();
		while((c=getchar())!='\n')
			poleVychozi[counter++] = c ;
		poleVychozi[counter] = 0;
		
		int length = 0;
		counter = 0;
		
		//upraveni retezce
		while(poleVychozi[counter]){
			if (poleVychozi[counter]==' '){
				counter++; 
				continue;
			}
			if (poleVychozi[counter] >= 'a' && poleVychozi[counter] <= 'z')
				poleVychozi[counter] = poleVychozi[counter] - 'a' + 'A';
			pole[length] = poleVychozi[counter];
			counter++;
			length++;
		}
		pole[length] = 0;
	
		if (N >= length) {
			printf("%s\n",pole);
			continue;
		}
		
		int pocatek = 0;
		counter = 0;
		
		//kodovani
		while(pocatek<N){
			int position = pocatek;
			while(position < length){
				poleVychozi[position] = pole[counter];
				position += N;
				counter++;
			}
			pocatek++;
		}
		poleVychozi[length] = 0;
		printf("%s\n",poleVychozi);
	}
	return 0;
}